Chromosome Breakage
Chromosomes
Chromosome Mapping
Chromosome Fragility
Chromosome Aberrations
Chromosome Fragile Sites
Chromosome Banding
Chromosome Disorders
X Chromosome
In Situ Hybridization, Fluorescence
Sex Chromosomes
Chromosomes, Human, Pair 1
Fanconi Anemia
Chromosomes, Human
Micronucleus Tests
Aneuploidy
Telomere
Chromosomes, Bacterial
Mitosis
Chromosomes, Human, Pair 11
Centromere
Chromosomes, Human, Pair 7
Molecular Sequence Data
DNA Damage
Base Sequence
Micronuclei, Chromosome-Defective
Chromosomes, Human, Pair 17
Translocation, Genetic
Sister Chromatid Exchange
Chromosomes, Human, Pair 6
Chromosomes, Human, Pair 9
Recombination, Genetic
Aphidicolin
Chromosomes, Fungal
Chromosomes, Plant
Chromosomes, Human, Pair 21
Chromosomal Instability
X-Rays
Chromosomes, Human, 6-12 and X
Chromosomes, Human, Pair 16
Chromosomes, Human, Pair 2
Mutation
Chromosomes, Human, Pair 4
Chromosomes, Human, Pair 22
Chromosomes, Human, Pair 8
Chromosomes, Mammalian
Chromosomes, Human, Pair 13
Chromosomes, Human, Pair 10
DNA
Chromosomes, Human, Y
Chromosomes, Human, Pair 19
Lymphocytes
Chromosomes, Artificial, Bacterial
Chromosomes, Human, X
Zea mays
Chromosomes, Human, 1-3
Chromosomes, Human, Pair 12
Chromosome Painting
Chromosomes, Human, Pair 5
Fanconi Anemia Complementation Group D2 Protein
Chromosomes, Human, Pair 14
DNA Transposable Elements
Chromosomes, Human, Pair 15
Chromosomes, Artificial, Yeast
Chromosomes, Human, Pair 18
Chromosomes, Human, 16-18
DNA Repair
Chromosomes, Human, Pair 20
Genetic Linkage
Chromosomes, Human, 13-15
Chromosome Inversion
Cloning, Molecular
Chromosomes, Human, 21-22 and Y
Genetic Markers
DNA-Binding Proteins
Polymerase Chain Reaction
Chromosome Positioning
Saccharomyces cerevisiae
Chromosomes, Human, 4-5
X Chromosome Inactivation
Meiosis
Hybrid Cells
Metaphase
Chromosomes, Human, 19-20
Cells, Cultured
Crosses, Genetic
Phenotype
Pedigree
Lod Score
Microsatellite Repeats
Alleles
Cell Cycle Proteins
Models, Genetic
Chromatids
Nucleic Acid Hybridization
Blotting, Southern
Chromosomal Proteins, Non-Histone
Nuclear Proteins
Amino Acid Sequence
Nondisjunction, Genetic
Chromosomes, Artificial, Human
Kinetochores
Spindle Apparatus
Sequence Analysis, DNA
Equipment Failure
Genotype
Chromosome Walking
Repetitive Sequences, Nucleic Acid
Diploidy
DNA Probes
Evolution, Molecular
Gene Rearrangement
Drosophila melanogaster
Interphase
Mosaicism
Haplotypes
Heterozygote
Genes
DNA, Satellite
Plasmids
Polyploidy
Gene Deletion
Chromatin
Cytogenetic Analysis
Chromosome Breakpoints
Genome, Human
Cell Nucleus
DNA Topoisomerases, Type II
Haploidy
Escherichia coli
Polytene Chromosomes
Multigene Family
Polymorphism, Genetic
Gene Amplification
Prophase
Gene Dosage
Loss of Heterozygosity
Genome
Species Specificity
Cytogenetics
Karyotype
Cosmids
DNA Breaks, Double-Stranded
Genetic Predisposition to Disease
Genes, Lethal
Histones
Sex Chromosome Disorders
Monosomy
Spermatocytes
Sequence Tagged Sites
Genomic Instability
Cricetinae
Polymorphism, Restriction Fragment Length
Sequence Homology, Nucleic Acid
DNA Primers
Gene Duplication
Genes, Dominant
Triticum
Polymorphism, Single Nucleotide
Sequence Homology, Amino Acid
Intellectual Disability
Cell Cycle
Comet Assay
Philadelphia Chromosome
Mutagens
Azure Stains
Chromosomes, Archaeal
Saccharomyces cerevisiae Proteins
Contig Mapping
Drosophila
Microtubules
Ataxia Telangiectasia
Transcription, Genetic
Sequence Alignment
Telomere loss in somatic cells of Drosophila causes cell cycle arrest and apoptosis. (1/785)
Checkpoint mechanisms that respond to DNA damage in the mitotic cell cycle are necessary to maintain the fidelity of chromosome transmission. These mechanisms must be able to distinguish the normal telomeres of linear chromosomes from double-strand break damage. However, on several occasions, Drosophila chromosomes that lack their normal telomeric DNA have been recovered, raising the issue of whether Drosophila is able to distinguish telomeric termini from nontelomeric breaks. We used site-specific recombination on a dispensable chromosome to induce the formation of a dicentric chromosome and an acentric, telomere-bearing, chromosome fragment in somatic cells of Drosophila melanogaster. The acentric fragment is lost when cells divide and the dicentric breaks, transmitting a chromosome that has lost a telomere to each daughter cell. In the eye imaginal disc, cells with a newly broken chromosome initially experience mitotic arrest and then undergo apoptosis when cells are induced to divide as the eye differentiates. Therefore, Drosophila cells can detect and respond to a single broken chromosome. It follows that transmissible chromosomes lacking normal telomeric DNA nonetheless must possess functional telomeres. We conclude that Drosophila telomeres can be established and maintained by a mechanism that does not rely on the terminal DNA sequence. (+info)Der(22) syndrome and velo-cardio-facial syndrome/DiGeorge syndrome share a 1.5-Mb region of overlap on chromosome 22q11. (2/785)
Derivative 22 (der[22]) syndrome is a rare disorder associated with multiple congenital anomalies, including profound mental retardation, preauricular skin tags or pits, and conotruncal heart defects. It can occur in offspring of carriers of the constitutional t(11;22)(q23;q11) translocation, owing to a 3:1 meiotic malsegregation event resulting in partial trisomy of chromosomes 11 and 22. The trisomic region on chromosome 22 overlaps the region hemizygously deleted in another congenital anomaly disorder, velo-cardio-facial syndrome/DiGeorge syndrome (VCFS/DGS). Most patients with VCFS/DGS have a similar 3-Mb deletion, whereas some have a nested distal deletion endpoint resulting in a 1.5-Mb deletion, and a few rare patients have unique deletions. To define the interval on 22q11 containing the t(11;22) breakpoint, haplotype analysis and FISH mapping were performed for five patients with der(22) syndrome. Analysis of all the patients was consistent with 3:1 meiotic malsegregation in the t(11;22) carrier parent. FISH-mapping studies showed that the t(11;22) breakpoint occurred in the same interval as the 1.5-Mb distal deletion breakpoint for VCFS. The deletion breakpoint of one VCFS patient with an unbalanced t(18;22) translocation also occurred in the same region. Hamster-human somatic hybrid cell lines from a patient with der(22) syndrome and a patient with VCFS showed that the breakpoints occurred in an interval containing low-copy repeats, distal to RANBP1 and proximal to ZNF74. The presence of low-copy repetitive sequences may confer susceptibility to chromosome rearrangements. A 1.5-Mb region of overlap on 22q11 in both syndromes suggests the presence of dosage-dependent genes in this interval. (+info)Low-copy repeats mediate the common 3-Mb deletion in patients with velo-cardio-facial syndrome. (3/785)
Velo-cardio-facial syndrome (VCFS) is the most common microdeletion syndrome in humans. It occurs with an estimated frequency of 1 in 4, 000 live births. Most cases occur sporadically, indicating that the deletion is recurrent in the population. More than 90% of patients with VCFS and a 22q11 deletion have a similar 3-Mb hemizygous deletion, suggesting that sequences at the breakpoints confer susceptibility to rearrangements. To define the region containing the chromosome breakpoints, we constructed an 8-kb-resolution physical map. We identified a low-copy repeat in the vicinity of both breakpoints. A set of genetic markers were integrated into the physical map to determine whether the deletions occur within the repeat. Haplotype analysis with genetic markers that flank the repeats showed that most patients with VCFS had deletion breakpoints in the repeat. Within the repeat is a 200-kb duplication of sequences, including a tandem repeat of genes/pseudogenes, surrounding the breakpoints. The genes in the repeat are GGT, BCRL, V7-rel, POM121-like, and GGT-rel. Physical mapping and genomic fingerprint analysis showed that the repeats are virtually identical in the 200-kb region, suggesting that the deletion is mediated by homologous recombination. Examination of two three-generation families showed that meiotic intrachromosomal recombination mediated the deletion. (+info)Delineation of the critical deletion region for congenital heart defects, on chromosome 8p23.1. (4/785)
Deletions in the distal region of chromosome 8p (del8p) are associated with congenital heart malformations. Other major manifestations include microcephaly, intrauterine growth retardation, mental retardation, and a characteristic hyperactive, impulsive behavior. We studied genotype-phenotype correlations in nine unrelated patients with a de novo del8p, by using the combination of classic cytogenetics, FISH, and the analysis of polymorphic DNA markers. With the exception of one large terminal deletion, all deletions were interstitial. In five patients, a commonly deleted region of approximately 6 Mb was present, with breakpoints clustering in the same regions. One patient without a heart defect or microcephaly but with mild mental retardation and characteristic behavior had a smaller deletion within this commonly deleted region. Two patients without a heart defect had a more proximal interstitial deletion that did not overlap with the commonly deleted region. Taken together, these data allowed us to define the critical deletion regions for the major features of a del8p. (+info)Development and validation of a quantitative polymerase chain reaction assay to evaluate minimal residual disease for T-cell acute lymphoblastic leukemia and follicular lymphoma. (5/785)
The presence of occult disease in cancer patients after therapy is one of the major problems faced by oncologists. For example, although 95% of pediatric T-cell acute lymphoblastic leukemia (T-ALL) patients have a complete therapeutic response to multiagent chemotherapy, half will relapse, indicating that they must have harbored low levels of residual cancer cells at the end of therapy. Sensitive detection assays promise to help identify those patients that carry this minimal residual disease (MRD) and are at risk of relapse. We have developed and validated a quantitative polymerase chain reaction (PCR) assay targeting tumor-specific chromosomal rearrangements, including del(1) involving the tal-1 locus in pediatric T-ALL and t(14;18) involving the bcl-2 locus in follicular lymphoma. This quantitative PCR assay utilizes a synthetic internal calibration standard (ICS) that contains priming sequences identical to those found flanking the chromosomal rearrangement breakpoints. Using this ICS-PCR method, the limits of detection were 5 tumor cells at ratios of 1 tumor cell in 10(5) normal cells and a linear range up to 100% tumor cells. This ICS-PCR method has also performed well in terms of precision and accuracy as indicated by low coefficients of variation, minimal random, proportional, and constant errors, and good clinical sensitivity and specificity characteristics. This technique will allow for the evaluation of parameters such as the rate of therapeutic response and the levels of MRD as predictors of patient outcome. (+info)Nonrandom cytogenetic alterations in hepatocellular carcinoma from transgenic mice overexpressing c-Myc and transforming growth factor-alpha in the liver. (6/785)
Identification of specific and primary chromosomal alterations during the course of neoplastic development is an essential part of defining the genetic basis of cancer. We have developed a transgenic mouse model for liver neoplasia in which chromosomal lesions associated with both the initial stages of the neoplastic process and the acquisition of malignancy can be analyzed. Here we analyze chromosomal alterations in 11 hepatocellular carcinomas from the c-myc/TGF-alpha double-transgenic mice by fluorescent in situ hybridization with whole chromosome probes, single-copy genes, and 4'-6-diamidino-2-phenylindole (DAPI-) and G-banded chromosomes and report nonrandom cytogenetic alterations associated with the tumor development. All tumors were aneuploid and exhibited nonrandom structural and numerical alterations. A balanced translocation t(5:6)(G1;F2) was identified by two-color fluorescent in situ hybridization in all tumors, and, using a genomic probe, the c-myc transgene was localized near the breakpoint on derivative chromosome der 6. Partial or complete loss of chromosome 4 was observed in all tumors with nonrandom breakage in band C2. Deletions of chromosome 1 were observed in 80% of the tumors, with the most frequent deletion at the border of bands C4 and C5. An entire copy of chromosome 7 was lost in 80% of the tumors cells. Eighty-five percent of the tumor cells had lost one copy of chromosome 12, and the most common breakpoint on chromosome 12 occurred at band D3 (28%). A copy of chromosome 14 was lost in 72%, and band 14E1 was deleted in 32% of the tumor cells. The X chromosome was lost in the majority of the tumor cells. The most frequent deletion on the X chromosome involved band F1. We have previously shown that breakages of chromosomes 1, 6, 7, and 12 were observed before the appearance of morphologically distinct neoplastic liver lesions in this transgenic mouse model. Thus breakpoints on chromosome 4, 9, 14, and X appear to be later events in this model of liver neoplasia. This is the first study to demonstrate that specific sites of chromosomal breakage observed during a period of chromosomal instability in early stages of carcinogenesis are later involved in stable rearrangements in solid tumors. The identification of the 5;6 translocation in all of the tumors has a special significance, being the first balanced translocation reported in human and mouse hepatocellular carcinoma and having the breakpoint near a tumor susceptibility gene and myc transgene site of integration. Moreover, its early occurrence indicates that this is a primary and relevant alteration to the initiation of the neoplastic process. In addition, the concordance between the breakpoints observed during the early dysplastic stage of hepatocarcinogenesis and the stable deletions of chromosomes 1, 4, 6, 7, 9, and 12 in the tumors provides evidence for preferential site of genetic changes in hepatocarcinogenesis. (+info)Increased chromosomal instability in peripheral lymphocytes and risk of human gliomas. (7/785)
Brain tumors exhibit considerable chromosome instability (CIN), suggesting that genetic susceptibility may contribute to brain tumorigenesis. To test this hypothesis, in this pilot study, we examined for CIN in short-term lymphocyte cultures from 25 adult glioma patients and 28 age-, sex- and ethnicity-matched healthy controls (all Caucasian). We evaluated CIN by a multicolor fluorescence in situ hybridization assay using two probes: a classic satellite probe for a large heterochromatin breakage-prone region of chromosome 1 and an alpha satellite probe for a smaller region adjacent to the heterochromatin probe. Our results showed a significant increase in the mean number of spontaneous breaks per 1000 cells in glioma patients (mean +/- SD, 2.4+/-0.8) compared with controls (1.4+/-0.9; P < 0.001). By using the median number of breaks per 1000 cells in the controls as the cutoff value, we observed a crude odds ratio (OR) of 8.5 [95% confidence interval (CI) = 2.05-34.9, P < 0.001] for spontaneous breaks and brain tumor risk. After adjustment for age, sex and smoking status, the adjusted OR was 15.3 (95% CI, 2.71-87.8). A significant increase in cells with chromosome 1 aneuploidy (in the form of hyperdiploidy) (P < 0.001) was also observed in the glioma cases, with an adjusted OR of 6.6 (95% CI = 1.5-30, P < 0.05). These findings suggest that CIN can be detected in the peripheral blood lymphocytes of brain tumor patients and may be a marker for identifying individuals at risk. (+info)Rearrangements of chromosome band 1p36 in non-Hodgkin's lymphoma. (8/785)
We studied 850 consecutive cases of histologically ascertained pretreatment non-Hodgkin's lymphoma with cytogenetically abnormal clones. The diagnostic karyotypes revealed that 12% of these cases exhibited structural rearrangements involving chromosome band 1p36. Here, we describe the karyotypes of 53 cases containing a 1p36 rearrangement [often involving translocations of unknown material and presented as add(1)(p36)]. We used fluorescence in situ hybridization to determine the origin of the translocation partners. We report three different recurrent translocations involving 1p36. These include der(1)t(1;1)(p36;q21) (three cases), der(1)t(1;1)(p36;q25) (three cases), and der(1)t(1;9)(p36;q13) (four cases). Using cytogenetic and fluorescence in situ hybridization analyses, we have resolved the translocation partners in 31 cases. Rearrangements of band 1p36 were found among different histopathological subtypes. Alterations of 1p36 never occurred as a sole abnormality, and in 42 of 53 cases, alterations of the band 14q32 were observed. The t(14;18)(q32;q21) translocation was present in 35 cases. The significantly high occurrence of 1p36 breakpoint in structural rearrangements and its involvement in recurrent translocations suggest that the region is bearing gene(s) that are important in lymphomagenesis. Our study also showed that cytogenetically evident deletions were frequent in chromosome 1p, almost always involving the p36 region, whereas duplications were rare and never encompassed the p36 region. Chromosome band 1p36 harbors many candidate tumor suppressor genes, and we propose that one or more of these genes might be deleted or functionally disrupted as a molecular consequence of the rearrangements, thus contributing to lymphomagenesis. (+info)When a chromosome breaks, it can lead to genetic instability and potentially contribute to the development of diseases such as cancer. Chromosome breakage can also result in the loss or gain of genetic material, which can further disrupt normal cellular function and increase the risk of disease.
There are several types of chromosome breakage, including:
1. Chromosomal aberrations: These occur when there is a change in the number or structure of the chromosomes, such as an extra copy of a chromosome (aneuploidy) or a break in a chromosome.
2. Genomic instability: This refers to the presence of errors in the genetic material that can lead to changes in the function of cells and tissues.
3. Chromosomal fragile sites: These are specific regions of the chromosomes that are more prone to breakage than other regions.
4. Telomere shortening: Telomeres are the protective caps at the ends of the chromosomes, and their shortening can lead to chromosome breakage and genetic instability.
Chromosome breakage can be detected through cytogenetic analysis, which involves staining the cells with dyes to visualize the chromosomes and look for any abnormalities. The detection of chromosome breakage can help diagnose certain diseases, such as cancer, and can also provide information about the risk of disease progression.
In summary, chromosome breakage is a type of genetic alteration that can occur as a result of various factors, including exposure to radiation or chemicals, errors during cell division, or aging. It can lead to genetic instability and increase the risk of diseases such as cancer. Detection of chromosome breakage through cytogenetic analysis can help diagnose certain diseases and provide information about the risk of disease progression.
There are several types of chromosome fragility, including:
1. Fragile X syndrome: This is the most common form of chromosome fragility and is caused by an expansion of a CGG repeat in the FMR1 gene on the X chromosome. It is associated with intellectual disability, behavioral problems, and physical characteristics such as large ears and long faces.
2. Turner syndrome: This is a condition where one X chromosome is missing or partially deleted, leading to short stature, infertility, and other developmental delays.
3. Klinefelter syndrome: This is a condition where an individual has an extra X chromosome, leading to tall stature, small testes, and infertility.
4. Trisomy 13 and trisomy 18: These are conditions where there is an extra copy of chromosomes 13 or 18, leading to developmental delays and other physical and intellectual disabilities.
5. Chromosome breakage syndromes: These are conditions where there is a defect in the chromosome that increases the risk of breakage during cell division, leading to aneuploidy or structural changes. Examples include ataxia-telangiectasia and Nijmegen breakage syndrome.
Chromosome fragility can be diagnosed through a variety of methods, including karyotyping, fluorescence in situ hybridization (FISH), and array comparative genomic hybridization (aCGH). Treatment for chromosome fragility depends on the specific condition and may include medication, surgery, or other interventions.
There are several types of chromosome aberrations, including:
1. Chromosomal deletions: Loss of a portion of a chromosome.
2. Chromosomal duplications: Extra copies of a chromosome or a portion of a chromosome.
3. Chromosomal translocations: A change in the position of a chromosome or a portion of a chromosome.
4. Chromosomal inversions: A reversal of a segment of a chromosome.
5. Chromosomal amplifications: An increase in the number of copies of a particular chromosome or gene.
Chromosome aberrations can be detected through various techniques, such as karyotyping, fluorescence in situ hybridization (FISH), or array comparative genomic hybridization (aCGH). These tests can help identify changes in the chromosomal makeup of cells and provide information about the underlying genetic causes of disease.
Chromosome aberrations are associated with a wide range of diseases, including:
1. Cancer: Chromosome abnormalities are common in cancer cells and can contribute to the development and progression of cancer.
2. Birth defects: Many birth defects are caused by chromosome abnormalities, such as Down syndrome (trisomy 21), which is caused by an extra copy of chromosome 21.
3. Neurological disorders: Chromosome aberrations have been linked to various neurological disorders, including autism and intellectual disability.
4. Immunodeficiency diseases: Some immunodeficiency diseases, such as X-linked severe combined immunodeficiency (SCID), are caused by chromosome abnormalities.
5. Infectious diseases: Chromosome aberrations can increase the risk of infection with certain viruses, such as human immunodeficiency virus (HIV).
6. Ageing: Chromosome aberrations have been linked to the ageing process and may contribute to the development of age-related diseases.
7. Radiation exposure: Exposure to radiation can cause chromosome abnormalities, which can increase the risk of cancer and other diseases.
8. Genetic disorders: Many genetic disorders are caused by chromosome aberrations, such as Turner syndrome (45,X), which is caused by a missing X chromosome.
9. Rare diseases: Chromosome aberrations can cause rare diseases, such as Klinefelter syndrome (47,XXY), which is caused by an extra copy of the X chromosome.
10. Infertility: Chromosome abnormalities can contribute to infertility in both men and women.
Understanding the causes and consequences of chromosome aberrations is important for developing effective treatments and improving human health.
There are many different types of chromosome disorders, including:
1. Trisomy: This is a condition in which there is an extra copy of a chromosome. For example, Down syndrome is caused by an extra copy of chromosome 21.
2. Monosomy: This is a condition in which there is a missing copy of a chromosome.
3. Turner syndrome: This is a condition in which there is only one X chromosome instead of two.
4. Klinefelter syndrome: This is a condition in which there are three X chromosomes instead of the typical two.
5. Chromosomal translocations: These are abnormalities in which a piece of one chromosome breaks off and attaches to another chromosome.
6. Inversions: These are abnormalities in which a segment of a chromosome is reversed end-to-end.
7. Deletions: These are abnormalities in which a portion of a chromosome is missing.
8. Duplications: These are abnormalities in which there is an extra copy of a segment of a chromosome.
Chromosome disorders can have a wide range of effects on the body, depending on the type and severity of the condition. Some common features of chromosome disorders include developmental delays, intellectual disability, growth problems, and physical abnormalities such as heart defects or facial anomalies.
There is no cure for chromosome disorders, but treatment and support are available to help manage the symptoms and improve the quality of life for individuals with these conditions. Treatment may include medications, therapies, and surgery, as well as support and resources for families and caregivers.
Preventive measures for chromosome disorders are not currently available, but research is ongoing to understand the causes of these conditions and to develop new treatments and interventions. Early detection and diagnosis can help identify chromosome disorders and provide appropriate support and resources for individuals and families.
In conclusion, chromosome disorders are a group of genetic conditions that affect the structure or number of chromosomes in an individual's cells. These conditions can have a wide range of effects on the body, and there is no cure, but treatment and support are available to help manage symptoms and improve quality of life. Early detection and diagnosis are important for identifying chromosome disorders and providing appropriate support and resources for individuals and families.
Some common effects of chromosomal deletions include:
1. Genetic disorders: Chromosomal deletions can lead to a variety of genetic disorders, such as Down syndrome, which is caused by a deletion of a portion of chromosome 21. Other examples include Prader-Willi syndrome (deletion of chromosome 15), and Williams syndrome (deletion of chromosome 7).
2. Birth defects: Chromosomal deletions can increase the risk of birth defects, such as heart defects, cleft palate, and limb abnormalities.
3. Developmental delays: Children with chromosomal deletions may experience developmental delays, learning disabilities, and intellectual disability.
4. Increased cancer risk: Some chromosomal deletions can increase the risk of developing certain types of cancer, such as chronic myelogenous leukemia (CML) and breast cancer.
5. Reproductive problems: Chromosomal deletions can lead to reproductive problems, such as infertility or recurrent miscarriage.
Chromosomal deletions can be diagnosed through a variety of techniques, including karyotyping (examination of the chromosomes), fluorescence in situ hybridization (FISH), and microarray analysis. Treatment options for chromosomal deletions depend on the specific effects of the deletion and may include medication, surgery, or other forms of therapy.
There are currently no cures for Fanconi anemia, but bone marrow transplantation and other supportive therapies can help manage some of the symptoms and improve quality of life. Research into the genetics and molecular biology of Fanconi anemia is ongoing to better understand the disorder and develop new treatments.
Some of the common symptoms of Fanconi anemia include short stature, limb deformities, hearing loss, vision problems, and an increased risk of infections and cancer. Children with Fanconi anemia may also experience developmental delays, learning disabilities, and social and emotional challenges.
The diagnosis of Fanconi anemia is typically made based on a combination of clinical findings, laboratory tests, and genetic analysis. Treatment options for Fanconi anemia depend on the severity of the disorder and may include bone marrow transplantation, blood transfusions, antibiotics, and other supportive therapies.
Fanconi anemia is a rare disorder that affects approximately 1 in 160,000 births worldwide. It is more common in certain populations, such as Ashkenazi Jews and individuals of Spanish descent. Fanconi anemia can be inherited in an autosomal recessive pattern, meaning that a child must inherit two copies of the mutated gene (one from each parent) to develop the disorder.
Overall, Fanconi anemia is a complex and rare genetic disorder that requires specialized medical care and ongoing research to better understand its causes and develop effective treatments. With appropriate management and supportive therapies, individuals with Fanconi anemia can lead fulfilling lives despite the challenges associated with the disorder.
There are several types of aneuploidy, including:
1. Trisomy: This is the presence of an extra copy of a chromosome. For example, Down syndrome is caused by an extra copy of chromosome 21 (trisomy 21).
2. Monosomy: This is the absence of a chromosome.
3. Mosaicism: This is the presence of both normal and abnormal cells in the body.
4. Uniparental disomy: This is the presence of two copies of a chromosome from one parent, rather than one copy each from both parents.
Aneuploidy can occur due to various factors such as errors during cell division, exposure to certain chemicals or radiation, or inheritance of an abnormal number of chromosomes from one's parents. The risk of aneuploidy increases with age, especially for women over the age of 35, as their eggs are more prone to errors during meiosis (the process by which egg cells are produced).
Aneuploidy can be diagnosed through various methods such as karyotyping (examining chromosomes under a microscope), fluorescence in situ hybridization (FISH) or quantitative PCR. Treatment for aneuploidy depends on the underlying cause and the specific health problems it has caused. In some cases, treatment may involve managing symptoms, while in others, it may involve correcting the genetic abnormality itself.
In summary, aneuploidy is a condition where there is an abnormal number of chromosomes present in a cell, which can lead to various developmental and health problems. It can occur due to various factors and can be diagnosed through different methods. Treatment depends on the underlying cause and the specific health problems it has caused.
The presence of chromosome-defective micronuclei in cells can be an indication of genetic damage and may be used as a diagnostic marker for certain diseases or conditions, such as cancer or exposure to toxic substances. The frequency and distribution of these structures within a cell population can also provide information about the type and severity of genetic damage present.
In contrast to other types of micronuclei, which are typically smaller and less complex, chromosome-defective micronuclei are larger and more irregular in shape, and may contain fragmented or abnormal chromatin material. They can also be distinguished from other types of micronuclei by their specific staining properties and the presence of certain structural features, such as the presence of nucleoli or the absence of a membrane boundary.
Overall, the study of chromosome-defective micronuclei is an important tool for understanding the mechanisms of genetic damage and disease, and may have practical applications in fields such as cancer diagnosis and environmental health assessment.
https://www.medicinenet.com › Medical Dictionary › G
A genetic translocation is a change in the number or arrangement of the chromosomes in a cell. It occurs when a portion of one chromosome breaks off and attaches to another chromosome. This can result in a gain or loss of genetic material, which can have significant effects on the individual.
Genetic Translocation | Definition & Facts | Britannica
https://www.britannica.com › science › Genetic-tr...
Genetic translocation, also called chromosomal translocation, a type of chromosomal aberration in which a portion of one chromosome breaks off and attaches to another chromosome. This can result in a gain or loss of genetic material. Genetic translocations are often found in cancer cells and may play a role in the development and progression of cancer.
Translocation, Genetic | health Encyclopedia - UPMC
https://www.upmc.com › health-library › gene...
A genetic translocation is a change in the number or arrangement of the chromosomes in a cell. It occurs when a portion of one chromosome breaks off and attaches to another chromosome. This can result in a gain or loss of genetic material, which can have significant effects on the individual.
Genetic Translocation | Genetics Home Reference - NIH
https://ghr.nlm.nih.gov › condition › ge...
A genetic translocation is a change in the number or arrangement of the chromosomes in a cell. It occurs when a portion of one chromosome breaks off and attaches to another chromosome. This can result in a gain or loss of genetic material, which can have significant effects on the individual.
In conclusion, Genetic Translocation is an abnormality in the number or arrangement of chromosomes in a cell. It occurs when a portion of one chromosome breaks off and attaches to another chromosome, resulting in a gain or loss of genetic material that can have significant effects on the individual.
Causes of Chromosomal Instability:
1. Genetic mutations: Mutations in genes that regulate the cell cycle or chromosome segregation can lead to CIN.
2. Environmental factors: Exposure to certain environmental agents such as radiation and certain chemicals can increase the risk of developing CIN.
3. Errors during DNA replication: Mistakes during DNA replication can also lead to CIN.
Types of Chromosomal Instability:
1. Aneuploidy: Cells with an abnormal number of chromosomes, either more or fewer than the normal diploid number (46 in humans).
2. Structural changes: Deletions, duplications, inversions, translocations, and other structural changes can occur in the chromosomes.
3. Unstable chromosome structures: Chromosomes with abnormal shapes or structures, such as telomere shortening, centromere instability, or chromosome breaks, can also lead to CIN.
Effects of Chromosomal Instability:
1. Cancer: CIN can increase the risk of developing cancer by disrupting normal cellular processes and leading to genetic mutations.
2. Aging: CIN can contribute to aging by shortening telomeres, which are the protective caps at the ends of chromosomes that help maintain their stability.
3. Neurodegenerative diseases: CIN has been implicated in the development of certain neurodegenerative diseases such as Alzheimer's and Parkinson's.
4. Infertility: CIN can lead to infertility by disrupting normal meiotic recombination and chromosome segregation during gametogenesis.
Detection and Diagnosis of Chromosomal Instability:
1. Karyotyping: This is a technique used to visualize the entire set of chromosomes in a cell. It can help identify structural abnormalities such as deletions, duplications, or translocations.
2. Fluorescence in situ hybridization (FISH): This technique uses fluorescent probes to detect specific DNA sequences or proteins on chromosomes. It can help identify changes in chromosome structure or number.
3. Array comparative genomic hybridization (aCGH): This technique compares the genetic material of a sample to a reference genome to identify copy number changes.
4. Next-generation sequencing (NGS): This technique can identify point mutations and other genetic changes in DNA.
Treatment and Management of Chromosomal Instability:
1. Cancer treatment: Depending on the type and stage of cancer, treatments such as chemotherapy, radiation therapy, or surgery may be used to eliminate cancer cells with CIN.
2. Prenatal testing: Pregnant women with a family history of CIN can undergo prenatal testing to detect chromosomal abnormalities in their fetuses.
3. Genetic counseling: Individuals with a family history of CIN can consult with a genetic counselor to discuss risk factors and potential testing options.
4. Lifestyle modifications: Making healthy lifestyle choices such as maintaining a balanced diet, exercising regularly, and not smoking can help reduce the risk of developing cancer and other diseases associated with CIN.
In conclusion, chromosomal instability is a common feature of many human diseases, including cancer, and can be caused by a variety of factors. The diagnosis and management of CIN require a multidisciplinary approach that includes cytogenetic analysis, molecular diagnostics, and clinical evaluation. Understanding the causes and consequences of CIN is crucial for developing effective therapies and improving patient outcomes.
Inversions are classified based on their location along the chromosome:
* Interstitial inversion: A segment of DNA is reversed within a larger gene or group of genes.
* Pericentric inversion: A segment of DNA is reversed near the centromere, the region of the chromosome where the sister chromatids are most closely attached.
Chromosome inversions can be detected through cytogenetic analysis, which allows visualization of the chromosomes and their structure. They can also be identified using molecular genetic techniques such as PCR (polymerase chain reaction) or array comparative genomic hybridization (aCGH).
Chromosome inversions are relatively rare in the general population, but they have been associated with various developmental disorders and an increased risk of certain diseases. For example, individuals with an inversion on chromosome 8p have an increased risk of developing cancer, while those with an inversion on chromosome 9q have a higher risk of developing neurological disorders.
Inversions can be inherited from one or both parents, and they can also occur spontaneously as a result of errors during DNA replication or repair. In some cases, inversions may be associated with other genetic abnormalities, such as translocations or deletions.
Overall, chromosome inversions are an important aspect of human genetics and can provide valuable insights into the mechanisms underlying developmental disorders and disease susceptibility.
Ring chromosomes are relatively rare, occurring in about 1 in every 10,000 to 20,000 births. They can be caused by a variety of factors, including genetic mutations, errors during cell division, or exposure to certain chemicals or radiation.
Ring chromosomes can affect anyone, regardless of age or gender. However, they are more common in certain populations, such as people with a family history of the condition or those who have certain medical conditions like Down syndrome or Turner syndrome.
The symptoms of ring chromosomes can vary widely and may include:
* Delayed growth and development
* Intellectual disability or learning difficulties
* Speech and language problems
* Vision and hearing impairments
* Heart defects
* Bone and joint problems
* Increased risk of infections and other health problems
Ring chromosomes can be diagnosed through a variety of tests, including karyotyping, fluorescence in situ hybridization (FISH), and microarray analysis. Treatment for the condition typically focuses on managing any associated health problems and may include medication, surgery, or other interventions.
In some cases, ring chromosomes can be inherited from one's parents. However, many cases are not inherited and occur spontaneously due to a genetic mutation. In these cases, the risk of recurrence in future pregnancies is generally low.
Overall, ring chromosomes are a complex and relatively rare chromosomal abnormality that can have a significant impact on an individual's health and development. With proper diagnosis and treatment, many people with ring chromosomes can lead fulfilling lives, but it is important to work closely with medical professionals to manage any associated health problems.
Some examples of multiple abnormalities include:
1. Multiple chronic conditions: An individual may have multiple chronic conditions such as diabetes, hypertension, arthritis, and heart disease, which can affect their quality of life and increase their risk of complications.
2. Congenital anomalies: Some individuals may be born with multiple physical abnormalities or birth defects, such as heart defects, limb abnormalities, or facial deformities.
3. Mental health disorders: Individuals may experience multiple mental health disorders, such as depression, anxiety, and bipolar disorder, which can impact their cognitive functioning and daily life.
4. Neurological conditions: Some individuals may have multiple neurological conditions, such as epilepsy, Parkinson's disease, and stroke, which can affect their cognitive and physical functioning.
5. Genetic disorders: Individuals with genetic disorders, such as Down syndrome or Turner syndrome, may experience a range of physical and developmental abnormalities.
The term "multiple abnormalities" is often used in medical research and clinical practice to describe individuals who have complex health needs and require comprehensive care. It is important for healthcare providers to recognize and address the multiple needs of these individuals to improve their overall health outcomes.
Trisomy is caused by an extra copy of a chromosome, which can be due to one of three mechanisms:
1. Trisomy 21 (Down syndrome): This is the most common type of trisomy and occurs when there is an extra copy of chromosome 21. It is estimated to occur in about 1 in every 700 births.
2. Trisomy 13 (Patau syndrome): This type of trisomy occurs when there is an extra copy of chromosome 13. It is estimated to occur in about 1 in every 10,000 births.
3. Trisomy 18 (Edwards syndrome): This type of trisomy occurs when there is an extra copy of chromosome 18. It is estimated to occur in about 1 in every 2,500 births.
The symptoms of trisomy can vary depending on the type of trisomy and the severity of the condition. Some common symptoms include:
* Delayed physical growth and development
* Intellectual disability
* Distinctive facial features, such as a flat nose, small ears, and a wide, short face
* Heart defects
* Vision and hearing problems
* GI issues
* Increased risk of infection
Trisomy can be diagnosed before birth through prenatal testing, such as chorionic villus sampling (CVS) or amniocentesis. After birth, it can be diagnosed through a blood test or by analyzing the child's DNA.
There is no cure for trisomy, but treatment and support are available to help manage the symptoms and improve the quality of life for individuals with the condition. This may include physical therapy, speech therapy, occupational therapy, and medication to manage heart defects or other medical issues. In some cases, surgery may be necessary to correct physical abnormalities.
The prognosis for trisomy varies depending on the type of trisomy and the severity of the condition. Some forms of trisomy are more severe and can be life-threatening, while others may have a more mild impact on the individual's quality of life. With appropriate medical care and support, many individuals with trisomy can lead fulfilling lives.
In summary, trisomy is a genetic condition that occurs when there is an extra copy of a chromosome. It can cause a range of symptoms and can be diagnosed before or after birth. While there is no cure for trisomy, treatment and support are available to help manage the symptoms and improve the quality of life for individuals with the condition.
There are several types of genetic nondisjunction, including:
1. Robertsonian translocation: This type of nondisjunction involves the exchange of genetic material between two chromosomes, resulting in a mixture of genetic information that can lead to developmental abnormalities.
2. Turner syndrome: This is a rare condition that occurs when one X chromosome is missing or partially present, leading to physical and developmental abnormalities in females.
3. Klinefelter syndrome: This condition occurs when an extra X chromosome is present, leading to physical and developmental abnormalities in males.
4. Trisomy 13: This condition occurs when there are three copies of chromosome 13, leading to severe developmental and physical abnormalities.
5. Trisomy 18: This condition occurs when there are three copies of chromosome 18, leading to severe developmental and physical abnormalities.
Genetic nondisjunction can be caused by various factors, including genetic mutations, errors during meiosis, or exposure to certain chemicals or radiation. It can be diagnosed through cytogenetic analysis, which involves studying the chromosomes of cells to identify any abnormalities.
Treatment for genetic nondisjunction depends on the specific type and severity of the condition. In some cases, no treatment is necessary, while in others, medication or surgery may be recommended. Prenatal testing can also be done to detect genetic nondisjunction before birth.
In summary, genetic nondisjunction is a chromosomal abnormality that occurs during meiosis and can lead to developmental and physical abnormalities. It can be caused by various factors and diagnosed through cytogenetic analysis. Treatment depends on the specific type and severity of the condition, and prenatal testing is available to detect genetic nondisjunction before birth.
The symptoms of chromosome duplication vary depending on the location and number of extra chromosomes present. Some common symptoms include:
* Delayed development and growth
* Intellectual disability
* Speech and language delays
* Physical abnormalities, such as heart defects or facial dysmorphism
* Increased risk of developing certain health problems, such as autism or epilepsy
Chromosome duplication can be diagnosed through a blood test or by analyzing cells from the body. Treatment is based on the specific symptoms and may include speech therapy, physical therapy, medication, or surgery.
Prognosis for individuals with chromosome duplication varies depending on the location and number of extra chromosomes present, as well as the presence of any other genetic conditions. Some individuals with chromosome duplication may have a good prognosis and lead normal lives, while others may experience significant health problems and developmental delays.
In some cases, chromosome duplication can be inherited from one or both parents, who may be carriers of the condition but do not exhibit any symptoms themselves. In other cases, chromosome duplication can occur spontaneously due to a mistake during cell division.
There is currently no cure for chromosome duplication, but early diagnosis and appropriate interventions can help manage symptoms and improve outcomes for affected individuals.
Examples of syndromes include:
1. Down syndrome: A genetic disorder caused by an extra copy of chromosome 21 that affects intellectual and physical development.
2. Turner syndrome: A genetic disorder caused by a missing or partially deleted X chromosome that affects physical growth and development in females.
3. Marfan syndrome: A genetic disorder affecting the body's connective tissue, causing tall stature, long limbs, and cardiovascular problems.
4. Alzheimer's disease: A neurodegenerative disorder characterized by memory loss, confusion, and changes in personality and behavior.
5. Parkinson's disease: A neurological disorder characterized by tremors, rigidity, and difficulty with movement.
6. Klinefelter syndrome: A genetic disorder caused by an extra X chromosome in males, leading to infertility and other physical characteristics.
7. Williams syndrome: A rare genetic disorder caused by a deletion of genetic material on chromosome 7, characterized by cardiovascular problems, developmental delays, and a distinctive facial appearance.
8. Fragile X syndrome: The most common form of inherited intellectual disability, caused by an expansion of a specific gene on the X chromosome.
9. Prader-Willi syndrome: A genetic disorder caused by a defect in the hypothalamus, leading to problems with appetite regulation and obesity.
10. Sjogren's syndrome: An autoimmune disorder that affects the glands that produce tears and saliva, causing dry eyes and mouth.
Syndromes can be diagnosed through a combination of physical examination, medical history, laboratory tests, and imaging studies. Treatment for a syndrome depends on the underlying cause and the specific symptoms and signs presented by the patient.
Polyploidy is a condition where an organism has more than two sets of chromosomes, which are the thread-like structures that carry genetic information. It can occur in both plants and animals, although it is relatively rare in most species. In humans, polyploidy is extremely rare and usually occurs as a result of errors during cell division or abnormal fertilization.
In medicine, polyploidy is often used to describe certain types of cancer, such as breast cancer or colon cancer, that have extra sets of chromosomes. This can lead to the development of more aggressive and difficult-to-treat tumors.
However, not all cases of polyploidy are cancerous. Some individuals with Down syndrome, for example, have an extra copy of chromosome 21, which is a non-cancerous form of polyploidy. Additionally, some people may be born with extra copies of certain genes or chromosomal regions due to errors during embryonic development, which can lead to various health problems but are not cancerous.
Overall, the term "polyploidy" in medicine is used to describe any condition where an organism has more than two sets of chromosomes, regardless of whether it is cancerous or non-cancerous.
Explanation: Genetic predisposition to disease is influenced by multiple factors, including the presence of inherited genetic mutations or variations, environmental factors, and lifestyle choices. The likelihood of developing a particular disease can be increased by inherited genetic mutations that affect the functioning of specific genes or biological pathways. For example, inherited mutations in the BRCA1 and BRCA2 genes increase the risk of developing breast and ovarian cancer.
The expression of genetic predisposition to disease can vary widely, and not all individuals with a genetic predisposition will develop the disease. Additionally, many factors can influence the likelihood of developing a particular disease, such as environmental exposures, lifestyle choices, and other health conditions.
Inheritance patterns: Genetic predisposition to disease can be inherited in an autosomal dominant, autosomal recessive, or multifactorial pattern, depending on the specific disease and the genetic mutations involved. Autosomal dominant inheritance means that a single copy of the mutated gene is enough to cause the disease, while autosomal recessive inheritance requires two copies of the mutated gene. Multifactorial inheritance involves multiple genes and environmental factors contributing to the development of the disease.
Examples of diseases with a known genetic predisposition:
1. Huntington's disease: An autosomal dominant disorder caused by an expansion of a CAG repeat in the Huntingtin gene, leading to progressive neurodegeneration and cognitive decline.
2. Cystic fibrosis: An autosomal recessive disorder caused by mutations in the CFTR gene, leading to respiratory and digestive problems.
3. BRCA1/2-related breast and ovarian cancer: An inherited increased risk of developing breast and ovarian cancer due to mutations in the BRCA1 or BRCA2 genes.
4. Sickle cell anemia: An autosomal recessive disorder caused by a point mutation in the HBB gene, leading to defective hemoglobin production and red blood cell sickling.
5. Type 1 diabetes: An autoimmune disease caused by a combination of genetic and environmental factors, including multiple genes in the HLA complex.
Understanding the genetic basis of disease can help with early detection, prevention, and treatment. For example, genetic testing can identify individuals who are at risk for certain diseases, allowing for earlier intervention and preventive measures. Additionally, understanding the genetic basis of a disease can inform the development of targeted therapies and personalized medicine."
There are several types of sex chromosome disorders, including:
1. Turner Syndrome: A condition that occurs in females who have only one X chromosome instead of two. This can lead to short stature, infertility, and other health problems.
2. Klinefelter Syndrome: A condition that occurs in males who have an extra X chromosome (XXY). This can lead to tall stature, breast enlargement, and infertility.
3. XXY Syndrome: A condition that occurs in individuals with two X chromosomes and one Y chromosome. This can lead to tall stature, breast enlargement, and fertility problems.
4. XYY Syndrome: A condition that occurs in individuals with an extra Y chromosome (XYY). This can lead to taller stature and fertility problems.
5. Mosaicism: A condition where there is a mixture of normal and abnormal cells in the body, often due to a genetic mutation that occurred during embryonic development.
6. Y chromosome variants: These are variations in the Y chromosome that can affect male fertility or increase the risk of certain health problems.
7. Uniparental disomy: A condition where an individual has two copies of one or more chromosomes, either due to a genetic mutation or because of a mistake during cell division.
8. Structural variations: These are changes in the structure of the sex chromosomes, such as deletions, duplications, or translocations, which can affect gene expression and increase the risk of certain health problems.
Sex chromosome disorders can be diagnosed through chromosomal analysis, which involves analyzing a person's cells to determine their sex chromosome makeup. Treatment for these disorders varies depending on the specific condition and may include hormone therapy, surgery, or other medical interventions.
Monosomy refers to a condition where an individual has only one copy of a particular chromosome, instead of the usual two copies present in every cell of the body. This can occur due to various genetic or environmental factors and can lead to developmental delays, intellectual disability, and physical abnormalities.
Other Defination:
Monosomy can also refer to the absence of a specific chromosome or part of a chromosome. For example, monosomy 21 is the condition where an individual has only one copy of chromosome 21, which is the chromosome responsible for Down syndrome. Similarly, monosomy 8p is the condition where there is a loss of a portion of chromosome 8p.
Synonyms:
Monosomy is also known as single chromosome deletion or single chromosome monosomy.
Antonyms:
Polysomy, which refers to the presence of extra copies of a particular chromosome, is the antonym of monosomy.
In Medical Terminology:
Monosomy is a genetic term that is used to describe a condition where there is only one copy of a particular chromosome present in an individual's cells, instead of the usual two copies. This can occur due to various factors such as errors during cell division or exposure to certain chemicals or viruses. Monosomy can lead to a range of developmental delays and physical abnormalities, depending on the location and extent of the missing chromosome material.
In Plain English:
Monosomy is a condition where a person has only one copy of a particular chromosome instead of two copies. This can cause developmental delays and physical abnormalities, and can be caused by genetic or environmental factors. It's important to note that monosomy can occur on any chromosome, but some specific types of monosomy are more common and well-known than others. For example, Down syndrome is a type of monosomy that occurs when there is an extra copy of chromosome 21.
There are several types of genomic instability, including:
1. Chromosomal instability (CIN): This refers to changes in the number or structure of chromosomes, such as aneuploidy (having an abnormal number of chromosomes) or translocations (the movement of genetic material between chromosomes).
2. Point mutations: These are changes in a single base pair in the DNA sequence.
3. Insertions and deletions: These are changes in the number of base pairs in the DNA sequence, resulting in the insertion or deletion of one or more base pairs.
4. Genomic rearrangements: These are changes in the structure of the genome, such as chromosomal breaks and reunions, or the movement of genetic material between chromosomes.
Genomic instability can arise from a variety of sources, including environmental factors, errors during DNA replication and repair, and genetic mutations. It is often associated with cancer, as cancer cells have high levels of genomic instability, which can lead to the development of resistance to chemotherapy and radiation therapy.
Research into genomic instability has led to a greater understanding of the mechanisms underlying cancer and other diseases, and has also spurred the development of new therapeutic strategies, such as targeted therapies and immunotherapies.
In summary, genomic instability is a key feature of cancer cells and is associated with various diseases, including cancer, neurodegenerative disorders, and aging. It can arise from a variety of sources and is the subject of ongoing research in the field of molecular biology.
There are various causes of intellectual disability, including:
1. Genetic disorders, such as Down syndrome, Fragile X syndrome, and Turner syndrome.
2. Congenital conditions, such as microcephaly and hydrocephalus.
3. Brain injuries, such as traumatic brain injury or hypoxic-ischemic injury.
4. Infections, such as meningitis or encephalitis.
5. Nutritional deficiencies, such as iron deficiency or iodine deficiency.
Intellectual disability can result in a range of cognitive and functional impairments, including:
1. Delayed language development and difficulty with communication.
2. Difficulty with social interactions and adapting to new situations.
3. Limited problem-solving skills and difficulty with abstract thinking.
4. Slow learning and memory difficulties.
5. Difficulty with fine motor skills and coordination.
There is no cure for intellectual disability, but early identification and intervention can significantly improve outcomes. Treatment options may include:
1. Special education programs tailored to the individual's needs.
2. Behavioral therapies, such as applied behavior analysis (ABA) and positive behavior support (PBS).
3. Speech and language therapy.
4. Occupational therapy to improve daily living skills.
5. Medications to manage associated behaviors or symptoms.
It is essential to recognize that intellectual disability is a lifelong condition, but with appropriate support and resources, individuals with ID can lead fulfilling lives and reach their full potential.
Synonyms: BCR-ABL fusion gene, t(9;22)(q34;q11), p210 protein, bcr-abl fusion transcript, breakpoint cluster region (BCR) - Abelson tyrosine kinase (ABLE) fusion gene.
Word Origin: Named after the city of Philadelphia, where it was first described in 1960.
The hallmark symptoms of AT are:
1. Ataxia: difficulty with coordination, balance, and gait.
2. Telangiectasias: small, red blood vessels visible on the skin, particularly on the face, neck, and arms.
3. Ocular telangiectasias: small, red blood vessels visible in the eyes.
4. Cognitive decline: difficulty with memory, learning, and concentration.
5. Seizures: episodes of abnormal electrical activity in the brain.
6. Increased risk of cancer: particularly lymphoma, myeloid leukemia, and breast cancer.
The exact cause of AT is not yet fully understood, but it is thought to be due to mutations in the ATM gene, which is involved in DNA damage response and repair. There is currently no cure for AT, but various treatments are available to manage its symptoms and prevent complications. These may include:
1. Physical therapy: to improve coordination and balance.
2. Occupational therapy: to assist with daily activities and fine motor skills.
3. Speech therapy: to improve communication and swallowing difficulties.
4. Medications: to control seizures, tremors, and other symptoms.
5. Cancer screening: regular monitoring for the development of cancer.
AT is a rare disorder, and it is estimated that only about 1 in 40,000 to 1 in 100,000 individuals are affected worldwide. It is important for healthcare providers to be aware of AT and its symptoms, as early diagnosis and intervention can improve outcomes for patients with this condition.
MRN complex
Type I topoisomerase
Chromosome instability
Artemis (protein)
Matthew Meselson
Chromosomal fragile site
Valery Soyfer
DNA repair and recombination protein RAD54-like
IFI6
SMC6
GeneMatcher
Chromosomal inversion
Diploidization
SMC5
Chromosome abnormality
Rad50
Robin Allshire
Chromosome instability syndrome
G0 phase
Alma Howard
Nijmegen breakage syndrome
Caren Norden
Barbara McClintock
Nondisjunction
Acute myelomonocytic leukemia
EcoEI R protein C-terminal domain
DNA damage (naturally occurring)
Marc Tischkowitz
Bloom syndrome
Mutagenesis
Caspase-activated DNase
Trichorrhexis invaginata
DNA damage theory of aging
Telomerase
Goniaea australasiae
Centromere
Serial killer
Benzene
DNA repair
Genome editing
Cleavage furrow
Microcephaly
List of OMIM disorder codes
FANCA
Z-DNA
Single-cell DNA template strand sequencing
FANCB
Tweedie distribution
List of diseases (T)
DNA supercoil
Wolf
Karyotype
Zygotic induction
Chromosome 22
Chromosome Breakage - MeSH - NCBI
Erowid.org: Erowid Reference 3791 : Chromosome Breakage in Children Treated with LSD-25 and UML-491 : Sankar DVS, Rozsa PW,...
Subjects: Chromosome Breakage - Digital Collections - National Library of Medicine Search Results
Dicentric chromosome breakage in Drosophila melanogaster is influenced by pericentric heterochromatin and occurs in...
Replication Stress Induces Global Chromosome Breakage in the Fragile X Genome - Fingerprint - Albert Einstein College of...
Common fragile sites and cancer (review)
NIH VideoCast - Demystifying Medicine 2014 - Chromosomal Translocation: Cellular Mechanism and Clinical Consequences
NIH Clinical Center Search the Studies: Study Number, Study Title
Clinical and research tests for all - Genetic Testing Registry (GTR) - NCBI
Publication Detail
Cholestasis in patients with Cockayne syndrome and suggested modified criteria for clinical diagnosis - PubMed
Advanced Search Results - Public Health Image Library(PHIL)
Cervical Cancer Medication: Chemotherapy Agents, Alkylating, Antineoplastics, Antimetabolite, Antineoplastics, Antimicrotubular...
Biomarkers Search
NIH Clinical Center Search the Studies: Study Number, Study Title
Cervical Cancer Medication: Chemotherapy Agents, Alkylating, Antineoplastics, Antimetabolite, Antineoplastics, Antimicrotubular...
Registration Dossier - ECHA
Bloom syndrome: MedlinePlus Genetics
DailyMed - KETOROLAC TROMETHAMINE injection, solution
DailyMed - KETOROLAC TROMETHAMINE tablet, film coated
NIOSHTIC-2 Search Results - Full View
RCSB PDB - 3L4K: Topoisomerase II-DNA cleavage complex, metal-bound
Research - Robert Crouch Lab | NICHD - Eunice Kennedy Shriver National Institute of Child Health and Human Development
MeSH Browser
St. Louis Airport | Public Assessment & Health Consultation | ATSDR
Chromosomal7
- These workers could not correlate effects of LSD-25 with human chromosomal breakage. (erowid.org)
- The present paper summarizes our findings of chromosomal breakage in psychiatric patients of the Children's Unit. (erowid.org)
- Chromosomal fragile sites are specific loci which are especially susceptible to forming gaps, breaks and rearrangements in metaphase chromosomes when cells are cultured under conditions that inhibit DNA replication. (nih.gov)
- In all patients chromosomal breakage studies revealed mild (45%) to moderate (60%) increase in frequency of chromatid and chromosome gaps and breaks versus 25% in normal controls. (nih.gov)
- 2. Sensitivity to chromosomal breakage as risk factor in young adults with oral squamous cell carcinoma. (nih.gov)
- Results obtained in this study were inconsistent and characterised by small increases in chromosomal aberrations (simple chromatid breakage) with and without activation by liver S9 mix (Union Carbide Corp. Bushy Run Research Center 1986). (europa.eu)
- While unequal crossing over could explain the generation of tandem duplications in proximity on the same chromosome, the generation of interspersed intra-chromosomal and inter-chromosomal duplications is difficult to explain by this mechanism [ 12 ]. (biomedcentral.com)
Chromatid3
- Our experimental approach was to induce sister chromatid exchange in a ring chromosome to generate a dicentric chromosome with a double chromatid bridge . (bvsalud.org)
- Chromosome structure consist of two sister chromatid is held together by Centromere. (myhealth.gov.my)
- Structural Maintenance of Chromosome (SMC) proteins are required for nuclear processes, including chromosome condensation, chromatid cohesion, and DNA repair. (novusbio.com)
Abnormalities1
- This is a Claymation that shows how Barbara McClintock's classic breakage-fusion-bridge cycle causes chromosome abnormalities. (chromosomesandcancer.com)
Fragility1
- The lack of hotspot conservation, along with a lack of response to aphidicolin , suggests that these breakage sites are not entirely analogous to CFS and may reveal new mechanisms of chromosome fragility . (bvsalud.org)
Fragile sites2
- In humans , breakage tends to occur in conserved hotspots called common fragile sites (CFS), especially during replication stress. (bvsalud.org)
- The common fragile sites are apparently present as a constant feature in all individuals and their clinical significance is that they might predispose chromosomes to breakage and rearrangement during cancer development. (nih.gov)
Chromatin1
- 1882: Wather Flemming was the first to illustrate the human chromosome, referred to as chromatin and for the first time the word "Mitosis" is used. (myhealth.gov.my)
Dicentric4
- Dicentric chromosome breakage in Drosophila melanogaster is influenced by pericentric heterochromatin and occurs in nonconserved hotspots. (bvsalud.org)
- By following the fate of dicentric chromosomes in Drosophila melanogaster , we find that breakage under tension also tends to occur in specific hotspots. (bvsalud.org)
- Additionally, the frequency of dicentric breakage and the durability of each chromosome 's spindle attachment vary significantly between the 3 chromosomes and are correlated with the origin of the centromere and the amount of pericentric heterochromatin . (bvsalud.org)
- The dicentric chromosome dic(20;22) is a recurrent abnormality in myelodysplastic syndromes and is a product of telomere fusion. (chromosomesandcancer.com)
Mutation1
- Spread of Mutation Change Along Chromosome. (nih.gov)
Occurs2
- For all 3 chromosomes , breakage occurs preferentially in several hotspots. (bvsalud.org)
- In addition, chromosome breakage occurs more frequently in affected individuals. (medlineplus.gov)
Subjects1
- have studied human leucocyte mitotic chromosomes both before and after administration of LSD-25 to the same group of subjects. (erowid.org)
Telomere5
- At the end of chromosome, a protective cap known as Telomere that protect from DNA degradation during chromosome breakage and prevent end to end fusion of chromosome. (myhealth.gov.my)
- Sometimes only part of the telomere erodes away - enough is lost that it no longer protects the chromosomes from sticking together. (chromosomesandcancer.com)
- This is the left-over telomere signature that tells us that this abnormal chromosome was made by the joining together of sticky chromosome ends that had their telomeres eroded away. (chromosomesandcancer.com)
- In our four cases we found that there was a small but non-functional piece of telomere DNA left behind where the two chromosomes joined. (chromosomesandcancer.com)
- For simplicity the Claymation shows telomere fusion in chromosomes that are dividing . (chromosomesandcancer.com)
Humans1
- The question of the effect of LSD-25 is an extremely important one, not only because of the psychopharmacological effects of LSD-25, but also because of the possibilty that many drugs may act on chromosomes, with resultant effects on the genetic information, both in humans and animals, during extended periods of drug administration, as is the case in psychiatric patients. (erowid.org)
Aberrant2
- This connection illustrates how an indispensable chromosome-disentangling machine auto-regulates DNA breakage to prevent the aberrant formation of mutagenic and cytotoxic genomic lesions. (rcsb.org)
- It is known that during RNA synthesis R-loops can form and that aberrant R-loop formation can result in chromosome breakage. (nih.gov)
Centromere1
- This assay discerns the presence of centromere within the MN to distinguish the MN containing centric chromosomes from those containing acentric fragments. (cdc.gov)
Fragments1
- The conventional MN assay does not discriminate between MN produced by acentric chromosome fragments from those arising due to whole lagging chromosomes that were not incorporated into daughter nuclei at the time of cell division. (cdc.gov)
Protein1
- In cell's nucleus, DNA is tightly coiled with histone protein and is packaged into thread-like macromolecule called Chromosome. (myhealth.gov.my)
Genes2
- These caused breakage-fusion-bridge events that caused a protective tumour suppressor gene to be lost, and may have also caused cancer-causing genes to multiply. (chromosomesandcancer.com)
- The 46 long strings of genes in each human cell are folded up to form chromosomes, which we can see down the microscope. (chromosomesandcancer.com)
Human2
- 1921: Theophilus Painter was the first to concluded that number of human chromosome is 24 with his observation under microscope. (myhealth.gov.my)
- Until 1956, scientist realized the real number of human chromosome is 23. (myhealth.gov.my)
Cycle1
- Chromosome breakage and cell cycle studies. (nih.gov)
Result1
- positive chromosome breakage result. (nih.gov)
Cancer2
- Chromosome breakage plays an important role in the evolution of karyotypes and can produce deleterious effects within a single individual, such as aneuploidy or cancer . (bvsalud.org)
- This complicated structure could not have been predicted by the standard methods of analysing cancer DNA or chromosomes . (chromosomesandcancer.com)
Form1
- When a cell prepares to divide to form two cells, the DNA that makes up the chromosomes is copied so that each new cell will have two copies of each chromosome, one from each parent. (medlineplus.gov)
Word1
- 1888: Waldeyer introduced the word "Chromosome" that is derived from Greek word. (myhealth.gov.my)
Video1
- The video shows one way that chromosomes (packages of DNA) can become disorganised. (chromosomesandcancer.com)
Unique1
- Surprisingly, we found that the hotspot locations are not conserved between the 3 chromosomes each displays a unique array of breakage hotspots. (bvsalud.org)
Points1
- The arrow points to green dots in the middle of a chromosome. (chromosomesandcancer.com)