Chromosomes human pair 21. Medical search. Frequent questions

This condition is most often caused by trisomy 21. (medlineplus.gov)
Trisomy 21 means that each cell in the body has three copies of chromosome 21 instead of the usual two copies. (medlineplus.gov)
Down syndrome is referred to as a common chromosome disorder which results when an individual has three copies of the 21st chromosome known as Trisomy 21 instead of two. (medicalsymptomsguide.com)
Jerome Lejeune a professer and his team found that Down syndrome,happends because of the trisomy 21. (timetoast.com)
Cytogenetic analysis in 386 patients showed 369 (95.5%) cases to be the result of regular trisomy 21, and translocation trisomy 21 was found in nine (2.5%) patients. (thetidenewsonline.com)
Although trisomic for almost the entire 21q arm, our patient shows no classical Down syndrome phenotype, but only a few minor anomalies found in trisomy 21 and in monosomy of proximal 21q, respectively. (johnshopkins.edu)
Trisomy 21 , the most common form of Down syndrome caused by an extra copy of chromosome 21 in every cell. (njadvocates.com)
It occurs when a person has an extra copy of chromosome 21 - otherwise known as trisomy 21 - in each cell. (wewantscience.com)
In about 95% of cases, there is an extra separate chromosome 21 (trisomy 21), which is typically maternally derived. (msdmanuals.com)

The genes of human chromosome 21 identified by the genome efforts were investigated, and the success rates for de novo cloning, protein production, and antibody generation were 85, 76, and 56%, respectively. (nih.gov)
Identifying genes on each chromosome is an active area of genetic research. (medlineplus.gov)
Because researchers use different approaches to predict the number of genes on each chromosome, the estimated number of genes varies. (medlineplus.gov)
Chromosome 21 likely contains 200 to 300 genes that provide instructions for making proteins. (medlineplus.gov)
Researchers believe that having extra copies of genes on chromosome 21 disrupts the course of normal development, causing the characteristic features of Down syndrome and the increased risk of health problems associated with this condition. (medlineplus.gov)
In a healthy person, almost every cell in the body carries 23 pairs of chromosomes, which hold nearly all of the genes needed for human life. (oneofus.eu)
Most people have 46 chromosomes in each cell, divided into 23 pairs: people with Down syndrome (DS) have an extra copy of chromosome 21, which carries over 200 genes. (ucl.ac.uk)
In the new study, the team looked at the effect of extra genes from mouse chromosome 10 that are the same as those on human chromosome 21, on anxiety and memory - and also considered female mice, to take into account gender. (ucl.ac.uk)
To do this, mice that had been genetically modified to carry an extra copy of 37 distinct genes from mouse chromosome 10 were then compared to a control group of typically developing mice from the same litter. (ucl.ac.uk)
It arises from having three copies of chromosome 21 and is a genetic disorder in that some of the genes on this chromosome must produce the features of Down syndrome. (ucl.ac.uk)
Co-corresponding author, Professor Matthew Walker (UCL Queen Square Institute of Neurology), added: "Chromosome 21 is made up of hundreds of genes but we only worked with a mouse with 37 of them duplicated. (ucl.ac.uk)
We are now starting to understand the role of variation in regions that control the expression of genes and how that impacts human diseases. (ashg.org)
Genes have been identified on the Y chromosome that have been shown to be required for the prevention of cancer and cardiovascular disease," Walsh said via email. (cnn.com)
We have narrowed the interval containing the gene causing BBS on chromosome 16 to a 1.5 Mb interval and are analyzing trapped exons as possible candidate genes for BBS. (bgu.ac.il)
This information and technique will allow us in the future to locate genes or QTL detected in different mapping populations efficiently and fast on homologous chromosomes or even chromosomal regions. (elsevierpure.com)
We have constructed a genetic linkage map of 17 markers on the long arm of human chromosome 21, including six genes and two anonymous loci with a variable number of tandem repeats. (johnshopkins.edu)
Analysis of the chromosome revealed 127 known genes, 98 predicted genes and 59 pseudogenes. (elsevierpure.com)
This showed chromosomes carry genes and described the chromosome recombination. (timetoast.com)
Barbara McClintock found out that genes can jump around on chromosomes. (timetoast.com)
When Barbara figured out that genes can "jump" she than correlated microscopic arrangments of chromosome placements. (timetoast.com)
Located on the X chromosome itself, Xist produces a protein that spreads up and down the chromosome during female embryonic development, turning off its genes. (sciencedaily.com)
and the University of California, Santa Cruz, Genome Browser, to look for genes or genomic regions of chromosomes 1 and 19 thought to produce proteins that interact with Xist. (sciencedaily.com)
Chromosomes are small "packages" of genes that determine how a body functions both during pregnancy and after birth. (wewantscience.com)
The interaction of genes with each other and with environmental factors underlies many aspects of human health and disease. (who.int)
These conditions are described as genetic diseases because a defect in one or more genes or chromosomes leads to a pathological condition. (who.int)
The deletion of varying lengths of chromosomal material along the short arm of chromosome 11 is the underlying defect, and developmental abnormalities are related to the contiguous loss of neighboring genes. (medscape.com)
Until ten years ago, it was hoped that the mapping of the human genome - all our genes - would enable us to better understand the course of different diseases. (lu.se)

Here we report the sequence and gene catalogue of the long arm of chromosome 21. (elsevierpure.com)
To resolve this issue, we have now examined the inheritance of five polymorphic DNA markers from the proximal long arm of chromosome 21 in a large unselected series of pedi-grees with familial Alzheimer's disease. (mssm.edu)
Molecular analysis using polymorphic markers on chromosome 21 verified a very small monosomic segment of the proximal long arm of chromosome 21, and additionally trisomy of the remaining distal segment. (johnshopkins.edu)

Less commonly, Down syndrome occurs when part of chromosome 21 becomes attached (translocated) to another chromosome during the formation of reproductive cells (eggs and sperm) or very early in fetal development. (medlineplus.gov)
Affected people have two copies of chromosome 21 plus extra material from chromosome 21 attached to another chromosome, resulting in three copies of genetic material from chromosome 21. (medlineplus.gov)
Translocation , where a part of chromosome 21 attaches to another chromosome. (njadvocates.com)
About 3% of people with Down syndrome have the normal count of 46 chromosomes but have an extra chromosome 21 translocated to another chromosome (the resulting abnormal chromosome is still counted only as 1). (msdmanuals.com)
A 21q21q translocation chromosome, which occurs when the extra chromosome 21 is attached to another chromosome 21, is much less common. (msdmanuals.com)

Down syndrome is a genetic and physical disorder that is caused by an additional chromosome 21 within the human body of 46 chromosomes (23 pairs). (thetidenewsonline.com)
The most common translocation is t(14;21), in which a piece of an additional chromosome 21 is attached to chromosome 14. (msdmanuals.com)

A genetic rearrangement (translocation) involving chromosome 21 is associated with a type of blood cancer known as core binding factor acute myeloid leukemia (CBF-AML). (medlineplus.gov)
The translocation, written as t(8;21), fuses part of the RUNX1 gene from chromosome 21 with part of the RUNX1T1 gene (also known as ETO ) from chromosome 8. (medlineplus.gov)
The fusion protein produced from the t(8;21) translocation, called RUNX1-ETO, retains some functions of the two individual proteins. (medlineplus.gov)
Methods We performed cytogenetics studies and breakpoint analyses on a family with transmission of mosaicism for a derivative chromosome 8 (der(8)), resulting from an unbalanced translocation between the long arms of chromosomes 8 and 21 over three generations. (elsevierpure.com)
In about half of people with the t(14;21) translocation, both parents have normal karyotypes, indicating a de novo translocation. (msdmanuals.com)
The next most common translocation is t(21;22). (msdmanuals.com)
It is particularly important to determine whether a parent is a carrier of, or mosaic for, translocation 21q21q (such mosaics have some normal cells and some 45 chromosome cells with the 21q21q translocation). (msdmanuals.com)
In such cases, each offspring of a carrier of the translocation will either have Down syndrome or monosomy 21 (the latter is not typically compatible with life). (msdmanuals.com)

Relevant of mutagenicity and clastogenici- angiosarcomas of the liver, which carcinogens discussed in this chap- ty, including the induction of sister are rare tumours, were identified in ter do not include pharmaceutical chromatid exchange (SCE), chro- humans, rats, and mice exposed to drugs classified in Group 1, which mosomal aberrations (CA), and mi- vinyl chloride. (who.int)

Numerous (267) sets of STRPs were identified that represented the exact same loci yet were developed independently and had different primer pairs. (nih.gov)
Identification of the gene causing BBS on chromosome 16 could aid in the identification of the other BBS loci and could help in the understanding of RP and polygenic disorders such as obesity and hypertension. (bgu.ac.il)
A total of 207 BAC clones containing 155 loci were isolated and arranged into a map of linearly ordered overlapping clones over the proximal part of horse chromosome 21 (ECA21), which corresponds to the proximal half of the short arm of human chromosome 19 (HSA19p) and part of HSA5. (uaeu.ac.ae)
We thank Drs. H. Donis-Keller and P. Green of Collaborative Research, Inc., for providing the genotypic data for five loci on chromosome 21 (Donis-Keller et al. (johnshopkins.edu)
Several anonymous loci for monogenic disorders and predispositions for common complex disorders have also been mapped to this chromosome, and loss of heterozygosity has been observed in regions associated with solid tumours. (elsevierpure.com)
Two recent genetic linkage studies revealed co-segregation of familial Alzheimer disease with the D21S1/S11 and D21S16 loci on chromosome 21 (refs 3,4). (mssm.edu)

In Down syndrome, there is an additional copy of chromosome 21, resulting in three copies instead of the normal two copies. (mayoclinic.org)
Two copies of chromosome 21, one copy inherited from each parent, form one of the pairs. (medlineplus.gov)
The following chromosomal conditions are associated with changes in the structure or number of copies of chromosome 21. (medlineplus.gov)
Lawrence's work shows that the gene can shut down other chromosomes too, a finding that paves the way for treating a range of other "trisomy" disorders, such as Edward syndrome and Patau syndrome , caused by extra copies of chromosomes 18 and 13 respectively. (oneofus.eu)
Discovering anomalies in chromosomes, such as a missing copy of a chromosome or duplicate copies, was helped by the invention of karyotyping techniques that allow paired human chromosomes to be easily stained, arranged, and visualized. (ashg.org)
Trisomy is having three instead of 2 copies of chromosome 21. (timetoast.com)
However, says Barbara R. Migeon, M.D., professor of pediatrics at the Johns Hopkins University School of Medicine and a pioneer in X-inactivation research, she and her colleagues reported nearly four decades ago that in some human embryos with triploidy -- a condition in which there are three sets of chromosomes instead of the usual two -- two copies of the X chromosome remained active. (sciencedaily.com)
To identify the likely location of the repressor protein and the gene that codes for it, the researchers started by looking at cells from human embryos with different forms of chromosomal trisomy, a condition in which cells carry three copies of a particular chromosome instead of two. (sciencedaily.com)

In human genetics, a human Y-chromosome DNA haplogroup is a haplogroup defined by mutations in the non-recombining portions of DNA from the male-specific Y chromosome (called Y-DNA). (wikipedia.org)
Realizing the benefits of human genetics and genomics research for people everywhere. (ashg.org)
Recent research suggests the Y chromosome is also important for health and longevity, said Kenneth Walsh, a professor of biochemistry and molecular genetics at the University of Virginia School of Medicine, who was not involved in the new research. (cnn.com)
Certain chromosomes may be put in place to serve as a backup, or to function at a specific stage of a person's life (such as during elderly years when existing genetics isn't up to the task). (gizmodo.com)
Despite of the extraordinary importance that all new knowledge on human genetics will have in dental clinics, little efforts have been made to prepare undergraduates in relation to this new information and technology. (bvsalud.org)

This is because dogs have 39 sets of chromosomes whereas humans have 23. (wewantscience.com)

A UCL-led research team has, for the first time, identified a specific region of chromosome 21, which causes issues with memory function and anxiety in a mouse that models Down syndrome, a finding that provides valuable new insight into the condition in people. (ucl.ac.uk)
One QTL with a major effect was found to map to the centromere region of chromosome 3 in both crosses. (elsevierpure.com)

In 2000, researchers working on the Human Genome Project announced that they had determined the sequence of base pairs that make up this chromosome. (medlineplus.gov)
Interleukin-21 (IL-21) was first identified in 2000 through screening of a cDNA library from CD3+ human T cells [ 1 ]. (intechopen.com)
This was followed, in May 2000, by chromosome 21. (bbc.co.uk)

During the process of cell division and production of sperm and egg, an instructive alteration occurs in the 21st chromosome that causes the likelihood of Down syndrome. (thetidenewsonline.com)

Only one section of the human genome fit the bill with these criteria -- a stretch of DNA on the short arm of chromosome 19. (sciencedaily.com)
These syndromes result from the loss of chromosomal material from the short arm of chromosome 11. (medscape.com)
The pathogenic germline deletion of varying lengths of chromosomal material along the short arm of chromosome 11, including WT1 and PAX6 , is the underlying defect. (medscape.com)
WAGR syndrome is caused by the contiguous loss of chromosomal material from the short arm of chromosome 11. (medscape.com)

Dual color fluorescence in situ hybridization on metaphase and interphase chromosomes verified the relative order of some of the BACs and helped to orient them accurately in the contigs. (uaeu.ac.ae)
The centromere is only characterized by a secondary constriction (with a centromeric index of a G chromosome) at an unexpected distal position, but fluorescence in situ hybridization (FISH) with either chromosome specific or with all human centromeres alpha satellite DNA shows no cross hybridization. (johnshopkins.edu)

These cell division abnormalities result in an extra partial or full chromosome 21. (mayoclinic.org)
DNA solves crimes, allows correct pairing of organ donors and recipients, facilitates prenatal testing for in utero abnormalities and creates clones. (sltrib.com)
Chromosome 21 abnormalities can cause intellectual disability, delayed development, and characteristic facial features. (medlineplus.gov)
Background Mosaicism for chromosomal structural abnormalities, other than marker or ring chromosomes, is rarely inherited. (elsevierpure.com)
It is one of the most commonly occurring chromosomal abnormalities in humans. (thetidenewsonline.com)
In fact, it is considered rare for dogs to have the same chromosome abnormalities as people do, and the testing needed for identifying this disease is not available. (wewantscience.com)

There are 23 pairs of chromosomes, for a total of 46. (mayoclinic.org)
We humans have 23 pairs, for a total of 46. (gizmodo.com)
In each cell, most humans have 23 pairs of chromosomes, for a total of 46. (sciencedaily.com)

Polymerase chain reaction analysis of each case was carried out using a panel of 12 polymorphic microsatellite markers, specific for chromosomes 13, 18, and 21. (dundee.ac.uk)

Oncogenic transcription factors such as the leukemic fusion protein RUNX1/ETO, which drives t(8;21) acute myeloid leukemia (AML), constitute cancer-specific but highly challenging therapeutic targets. (prinsesmaximacentrum.nl)

Down syndrome results when abnormal cell division involving chromosome 21 occurs. (mayoclinic.org)
Down syndrome occurs when there's an extra copy of chromosome 21, and it affects a person's health. (wewantscience.com)

Currently, there is no way to confirm that dogs have down syndrome because there is no way to test the dog's DNA to see if it has an abnormal chromosome. (wewantscience.com)

This der(21) chromosome has a deletion of 21p and of proximal 21q, whereas the main portion of 21q is duplicated leading to a mirror-symmetric appearance with the mirror axis at the breakpoint. (johnshopkins.edu)

Changes involving chromosome 21 can include a missing segment of the chromosome in each cell (partial monosomy 21) and a circular structure called ring chromosome 21. (medlineplus.gov)

Two linkage maps based on a hybrid cross (N. vitripennis x N. longicornis) were constructed using STS, RAPD and microsatellite markers, where 17 of the linked STS markers were developed from single microdissected banded chromosomes. (elsevierpure.com)

Down syndrome is a genetic disorder caused when abnormal cell division results in an extra full or partial copy of chromosome 21. (mayoclinic.org)
The tragic extra copy - or partial copy - of Chromosome 21 is a troubling abnormality, presenting questions of both reason and belief for parents and lawmakers. (sltrib.com)
A person with Down syndrome has an extra copy (or an extra partial copy) of chromosome 21. (njadvocates.com)
This results in an extra partial or full chromosome. (emelhospital.org)

Chromosome 21 was the second human chromosome to be fully sequenced. (medlineplus.gov)
Scientists have fully sequenced the Y chromosome for the first time, uncovering information that could have implications for the study of male infertility and other health problems. (cnn.com)

For researchers who wish to convert T/S ratio to base pairs (bp), the formula is (3,274 + 2,413 * (T/S)). The conversion from T/S ratio to bp is calculated based on comparison of telomeric restriction fragment (TRF) length from Southern blot analysis and T/S ratios using DNA samples from the human diploid fibroblast cell line IMR90 at different population doublings. (cdc.gov)
HG consists of 23 pairs of chromosomes existing in all diploid cells of human beings, where DNA is found and all genetic features of an individual is stored 6 . (bvsalud.org)

In a very small percentage of cases, Down syndrome results from an extra copy of chromosome 21 in only some of the body's cells. (medlineplus.gov)
People with Down's syndrome have an extra copy of chromosome 21. (lawcf.org)
Down's syndrome arises when cells have an extra copy of chromosome 21. (oneofus.eu)
Chromosomal conditions such as Down syndrome, where an individual has an extra copy of chromosome 21, were initially discovered through karyotyping. (ashg.org)
An extra copy of chromosome 21 causes Down syndrome, the most frequent genetic cause of significant mental retardation, which affects up to 1 in 700 live births. (elsevierpure.com)
Mosaic , where only some cells have an extra copy of chromosome 21. (njadvocates.com)
Intriguingly, some people (37%) have an extra chunk of DNA in chromosome 20 and could have an extra copy of a specific gene of unknown function. (bbc.co.uk)
If a person has down syndrome, they have an extra copy of chromosome 21, which causes problems with their physical and mental development. (wewantscience.com)
Subject A has a large deletion on chromosome 11 that removes one copy of the BDNF gene. (medscape.com)

A treatment based on the work remains a distant hope, but scientists in the field said the feat was the first major step towards a "chromosome therapy" for Down's syndrome. (oneofus.eu)
The long-range possibility - and it's an uncertain possibility - is a chromosome therapy for Down's syndrome. (oneofus.eu)
Lawrence's team used "genome editing", a procedure that allows DNA to be cut and pasted, to drop a gene called XIST into the extra chromosome in cells taken from people with Down's syndrome. (oneofus.eu)
The work is already helping scientists to tease apart how an extra chromosome 21 causes a raft of problems that strike people with Down's syndrome at various ages. (oneofus.eu)
The US team has already begun work that aims to prevent Down's syndrome in mice, by silencing the extra chromosome 21 in early-stage embryos. (oneofus.eu)

We report on a mentally retarded child with multiple minor anomalies and an unusually rearranged chromosome 21. (johnshopkins.edu)
Anomalies that affect autosomes (the 22 paired chromosomes that are alike in males and females) are more common than those that affect sex chromosomes. (msdmanuals.com)

The more detailed information provided by the new Y reference sequence will make it easier to study conditions and disorders linked to the chromosome, such as lack of sperm production that leads to infertility. (cnn.com)
They narrowed their search to a few candidate regions, then turned to a third database, Decipher, which makes it possible to compare human genome variants on tens of thousands of patients with genetic disorders worldwide. (sciencedaily.com)
Some genetic diseases, such as haemophilia, are carried on the X-chromosome (these X-linked disorders occur mainly in men). (who.int)

The Human Genome Project (HGP) started in the United States of America aiming at sequencing and mapping the human genetic code. (bvsalud.org)

These analyses are fundamental in the design of control specimens present C-heterochromatic blocks in most of campaigns because their results will help determine the their 22 chromosomes, whereas non-Andean specimens have only 4-7 autosomes with C-banding. (cdc.gov)
pairs of autosomes and 1 pair of sex chromosomes (XY in Institut de Recherche pour le Développement, Montpellier, males, XX in females) (8). (cdc.gov)

Now, the same group of researchers has filled in the missing information, publishing a complete Y chromosome sequence Wednesday in the journal Nature . (cnn.com)
The work is part of the ongoing Human Genome Project, an international effort to sequence (read) the genetic make-up of humans. (bbc.co.uk)
Once again, we are seeing the fruits of the two key commitments of the Human Genome Project: to make the sequence freely available and to produce a quality finished sequence. (bbc.co.uk)
The sequence of chromosome 22 was revealed two years ago. (bbc.co.uk)

Chromosome 21 is the smallest human chromosome, spanning about 48 million base pairs (the building blocks of DNA) and representing 1.5 to 2 percent of the total DNA in cells. (medlineplus.gov)
However, over half of the sequences within the Y chromosome, the smallest and most complicated of the 46 human chromosomes, remained unknown. (cnn.com)
Chromosome 21 is the smallest human autosome. (elsevierpure.com)

While comparisons across studies of telomere length in base pairs are commonly done, it is not highly accurate. (cdc.gov)

There are two types: autosomal and sex chromosomes. (gizmodo.com)
Because having two active X chromosomes is lethal very early in development -- before a new embryo even implants into the uterine wall -- Migeon and her colleagues focused on autosomal trisomies. (sciencedaily.com)

The signaling mechanisms of IL-21 in different cell types have been identified. (intechopen.com)
Humans typically have a pair of sex chromosomes in each cell. (cnn.com)
Chromosomes offer a way for nuclear material to be packaged, protected, and maintained as it's passed from cell to cell. (gizmodo.com)
Walter Flemming was one of the first cytologists to fully detail the movement of chromosomes during mitosis, as well as cell division. (timetoast.com)
In humans, each cell contains 23 pairs of chromosomes. (wewantscience.com)
Down syndrome mosaicism presumably results from nondisjunction (when chromosomes fail to pass to separate cells) during cell division in the embryo. (msdmanuals.com)
People with mosaic Down syndrome have two cell lines, one with the normal 46 chromosomes and another with 47 chromosomes, including an extra chromosome 21. (msdmanuals.com)

The Y chromosome was a particularly hard nut to crack because it is unusually repetitive. (cnn.com)

Conclusion Mosaicism in the proband, his half-sister and half-cousin resulting from loss of chromosome 21 material from the der(8) appears to be a postzygotic event due to the genomic instability of ITS and associated with selective growth advantage of normal cells. (elsevierpure.com)

The reversion of the inherited der(8) to a normal chromosome 8 in this family resembles revertant mosaicism of point mutations. (elsevierpure.com)

[4] In the first stages of embryonic development, male and female embryos are almost morphologically identical, however, eventually, due to the expression of the sex-determining gene, on the Y chromosome, the testes begin to develop. (wikibooks.org)
After nearly 40 years of searching, researchers report they have identified a part of the human genome that appears to block an RNA responsible for keeping only a single X chromosome active when new female embryos are formed, effectively allowing for the generally lethal activation of more than one X chromosome during development. (sciencedaily.com)
The research team reported finding examples of trisomies in every chromosome in embryos that survived at least until later stages, except chromosomes 1 or 19. (sciencedaily.com)
The team reasoned that if the repressor was in a region that was duplicated, it would work overtime and turn off Xist on both X chromosomes, leaving both the X chromosomes active and selectively changing the survival of male vs. female embryos. (sciencedaily.com)

In an elegant series of experiments, US researchers took cells from people with DS and silenced the extra chromosome that causes the condition. (oneofus.eu)
Beginning in the 1950s, researchers first used a molecular technique called karyotyping to visualize human chromosomes and their differences linked to conditions such as Down syndrome. (ashg.org)
Sex chromosome researchers have long known that the vast majority of human and other mammalian females have two X chromosomes, while the vast majority of males have a single X and a Y, and only one X chromosome is active in females. (sciencedaily.com)

Half the chromosomes come from the egg (the mother) and half come from the sperm (the father). (mayoclinic.org)
This XY chromosome pair includes the X chromosome from the egg and the Y chromosome from the sperm. (mayoclinic.org)

Charcot-Marie-Tooth disease, which causes degeneration of the peripheral nerves, is an example of a CNV disorder for which a duplication of a specific region in chromosome 17 is the most common cause. (ashg.org)
Our data suggest that Alzheimer's disease is not a single entity, but rather results from genetic defects on chromosome 21 and from other genetic or nongenetic factors. (mssm.edu)
It could also give an insight into variant Creutzfeldt-Jakob disease (vCJD), the human form of mad cow disease. (bbc.co.uk)
Only 21% cited the undergraduate program as a source of information, 56% recognized advances in disease prevention and 81% reported applicability in Dentistry. (bvsalud.org)
Understanding Genetic and Environmental Causes of Human Disease A recent article in the Archives of General Psychiatry by Hallmayer et al. (cdc.gov)

The female:male ratio of genetic distance varied across individual chromosomes in a remarkably consistent fashion, with peaks at the centromeres of all metacentric chromosomes. (nih.gov)

In females, it is perfect with two X-chromosomes. (mercinewyork.com)
Because so-called X-inactivation is essential for normal female embryo development in humans and other mammals, and two activated X chromosomes create an inherently fatal condition, the research may help explain the worldwide human sex ratio that has slightly favored males over females for as long as science has been able to measure it. (sciencedaily.com)
The 23rd pair is composed of the sex chromosomes, either two X's, in the cases of females, or an X and a Y, in the case of males. (sciencedaily.com)

It is also reported that human PITX2 insufficiency results in cellular and molecular changes leading to atrial electrical and structural remodeling linked to arrhythmogenesis 6 . (nature.com)
These techniques enabled the first examples of molecular characterization of human diseases. (ashg.org)

Scientists have deciphered the complete genetic instructions of a third chromosome, one of the 24 distinct bundles of DNA that carry our genetic material. (bbc.co.uk)

Introduction: The Human Genome Project (HGP) has allowed for advances in diagnosis and prevention of diseases. (bvsalud.org)

The research builds on a previous study by the same team, which examined the areas of chromosome 21 responsible for memory and decision-making problems in male mice that modelled Down syndrome. (ucl.ac.uk)
or each of these agents, carcinogenicity in rats and/or mice, els, differences in exposure con- there was sufficient evidence of car- for example for the liver (aflatoxins, ditions between studies in animals cinogenicity from studies in rats and/ trichloroethylene [TCE], and vinyl and in humans, or limitations in Part 1 · Chapter 1. (who.int)

Previous studies found that the XIST gene is crucial for normal human development. (oneofus.eu)
The XIST gene sits on the X chromosome, but is only active in women. (oneofus.eu)
Studies done elsewhere identified the mechanism behind the silencing of X chromosomes: a gene called Xist, short for X-inactive specific transcript. (sciencedaily.com)
The most likely explanation for this phenomenon, Migeon reasons, was that a protein that represses the X chromosome silencing activity of Xist was working overtime, allowing more than one X chromosome to remain activated. (sciencedaily.com)

While t(8;21) is important for leukemia development, one or more additional genetic changes are typically needed for the myeloid blasts to develop into cancerous leukemia cells. (medlineplus.gov)
However, we know less about the biological effects of IL-21 and its signaling mechanisms in leukemia cells and monocytes. (intechopen.com)
In this chapter, we will focus on IL-21's biological effects and signaling pathways as well as discuss the potential implications and applications of IL-21 in leukemia cells. (intechopen.com)

however, women only have X chromosomes, whilst men have both X and Y. The presence or absence of the Y chromosome enables biologists to determine the sex of an individual. (wikibooks.org)
According to biologists, we could create custom-built chromosomes to fix a variety of health problems, and even give us new abilities. (gizmodo.com)

Anatomy66

Organisms8

Diseases26

Chemicals and Drugs29

Analytical, Diagnostic and Therapeutic Techniques and Equipment26

Psychiatry and Psychology1

Phenomena and Processes174

Disciplines and Occupations2

Technology, Industry, Agriculture2

Information Science4

Health Care1

Trisomy 219

Genes27

Long arm of chromosome 213

Another chromosome5

Additional chromosome 212

Translocation8

Aberrations1

Loci6

Copies8

Genetics5

Sets of chromosomes1

Region of chromosome2

20003

21st chromosome1

Short arm of chromosome4

Fluorescence in situ hybri2

Abnormalities6

Total of 463

Polymorphic1

Acute myeloid1

Occurs2

Abnormal chromosome1

Proximal1

Monosomy1

Markers1

Partial4

Fully sequenced2

Diploid2

Copy9

Down's5

Anomalies2

Disorders3

Mapping1

Autosomes2

Sequence4

Smallest3

Base pairs1

Autosomal2

Cell7

Unusually1

Genomic1

Mosaicism1

Embryos4

Researchers3

Sperm2

Disease5

Centromeres1

Females3

Molecular2

DISTINCT1

Genome Project1

Mice2

XIST4

Leukemia3

Biologists2