• Patients carry from 230 to 4000 CGG repeats in the gene that causes fragile X syndrome, while unaffected individuals have up to 50 repeats and carriers of the disease have 60 to 230 repeats. (wikipedia.org)
  • Sometimes, a person may have more than the usual number of copies of a repeat sequence associated with a gene, but not enough to alter the function of that gene. (wikipedia.org)
  • The first main category these authors discuss is repeat expansions located within the promoter region of a gene or located close to, but upstream of, a promoter region of a gene. (wikipedia.org)
  • There is often increased methylation at CpG islands near the repeat region, resulting in a closed chromatin state, causing gene downregulation. (wikipedia.org)
  • For instance, if you've got a mutation caused by triplet repeat expansion, for instance in the Huntington's gene, where the trinucleotide repeats a CAG, you might have 17 CAGs in a normal chromosome. (hstalks.com)
  • But in a diseased chromosome, you might have 40 successive copies of CAG trinucleotides in the gene. (hstalks.com)
  • A novel gene containing a trinucleotide repeat that is expanded and unstable on Huntington's disease chromosomes. (nature.com)
  • Somatic and gonadal mosaicism of the Huntington disease gene CAG repeat in brain and sperm. (nature.com)
  • Huntington's disease (HD) is a progressive and fatal neurodegenerative disorder caused by an expanded CAG repeat in the huntingtin gene. (nature.com)
  • Individuals with juvenile onset usually have over 55 repeats, and they usually inherit the gene from their father. (jci.org)
  • In one region of the AR gene, a DNA segment known as CAG is repeated multiple times. (medlineplus.gov)
  • In most people, the number of CAG repeats in the AR gene ranges from fewer than 10 to about 36. (medlineplus.gov)
  • Spinal and bulbar muscular atrophy, a disorder of specialized nerve cells that control muscle movement (motor neurons), results from an expansion of the CAG trinucleotide repeat in the AR gene. (medlineplus.gov)
  • Huntington's disease is a genetic neurological disorder caused by a repeated expansion of the CAG trinucleotide, causing instability in the N-terminal of the gene coding for the Huntingtin protein. (benthamscience.com)
  • At the molecular level, HD occurs due to an increase in the number of CAG repeats in the first exon of the gene encoding the huntingtin protein. (frontiersin.org)
  • The expansion of the cytosine-adenine-guanine (CAG) trinucleotide in the HTT gene leads to the production of atypical protein. (medicalnewstoday.com)
  • Dr. Flannery also describes single gene sequencing, deletion/duplication testing chromosomal microarray (CMA) testing and detection of trinucleotide repeats. (genome.gov)
  • Fragile X is usually caused by a trinucleotide expansion in the FMR1 gene on the X chromosome. (uab.edu)
  • If a homozygous female, premutation, or full mutation is identified or suspected, a second tier of testing consists of Eco RI and Eag I restriction digest followed by Southern blot analysis using the DNA probe, StB12.3 to determine methylation status of the FMR1 gene and approximate number of trinucleotide repeats. (uab.edu)
  • abstract = "Huntington{\textquoteright}s disease is a fatal neurodegenerative disorder caused by an expanded CAG triplet repeat in the huntingtin (HTT) gene. (lu.se)
  • Association between androgen receptor gene CAG trinucleotide repeat length and testicular histology in older men. (bvsalud.org)
  • The first trinucleotide repeat disease to be identified was fragile X syndrome, which has since been mapped to the long arm of the X chromosome. (wikipedia.org)
  • The second DNA-triplet repeat disease, fragile X-E syndrome, was also identified on the X chromosome, but was found to be the result of an expanded CCG repeat. (wikipedia.org)
  • Here we show that replication fork pausing and CAG/CTG trinucleotide repeat instability are not linked, stable and unstable repeats exhibiting the same propensity to stall replication forks when integrated in a yeast natural chromosome. (edu.sa)
  • We also compare the codon-like trinucleotide (CLT) extensions of human and chimpanzee chromosome 4. (srce.hr)
  • In this second type of disorder, large repeat expansions in DNA are transcribed into pathogenic RNAs that form nuclear RNA foci. (wikipedia.org)
  • Translation of these repeat expansions occurs mostly through two mechanisms. (wikipedia.org)
  • Today I'm going to tell you about microsatellites, and trinucleotide repeat expansions diseases. (hstalks.com)
  • Here, we report the discovery of exonic GGC trinucleotide repeat expansions, encoding poly-glycine, in zinc finger homeobox 3 (ZFHX3) in these families. (lu.se)
  • We also found ZFHX3 repeat expansions in three additional families, all from the region of Skåne in southern Sweden. (lu.se)
  • Our findings demonstrate that SCA4 is caused by repeat expansions in ZFHX3. (lu.se)
  • Trinucleotide repeat expansions are responsible for at least two dozen neurological disorders. (edu.sa)
  • Mechanisms leading to these large expansions of repeated DNA are still poorly understood. (edu.sa)
  • It was proposed that transient stalling of the replication fork by the repeat tract might trigger slippage of the newly-synthesized strand over its template, leading to expansions or contractions of the triplet repeat. (edu.sa)
  • Finally, we show that overexpressing MSH2 favors the formation of heteroduplex regions, leading to an increase in contractions and expansions of CAG/CTG repeat tracts during replication, these heteroduplexes being dependent on both MSH3 and MSH6. (edu.sa)
  • Repeat expansions in NOP56 are a cause of spinocerebellar ataxia Type 36 in the British population. (cdc.gov)
  • The chromosomal instability resulting from this trinucleotide expansion presents clinically as intellectual disability, distinctive facial features, and macroorchidism in males. (wikipedia.org)
  • Our results show that Msh2 is required for somatic instability of the CAG repeat. (nature.com)
  • Figure 3: Levels of CAG repeat instability in various tissues from Msh2 -/- , Msh2 +/- and Msh2 +/+ mice. (nature.com)
  • Trottier, Y., Biancalana, V. & Mandel, J.L. Instability of CAG repeats in Huntington's disease: relation to parental transmission and age of onset. (nature.com)
  • Instability of highly expanded CAG repeats in mice transgenic for the Huntington's disease mutation. (nature.com)
  • Trinucleotide repeat disorders, also known as microsatellite expansion diseases, are a set of over 50 genetic disorders caused by trinucleotide repeat expansion, a kind of mutation in which repeats of three nucleotides (trinucleotide repeats) increase in copy numbers until they cross a threshold above which they cause developmental, neurological or neuromuscular disorders. (wikipedia.org)
  • Trinucleotide repeats are a subset of a larger class of unstable microsatellite repeats that occur throughout all genomes. (wikipedia.org)
  • Trinucleotide repeat disorders and the related microsatellite repeat disorders affect about 1 in 3,000 people worldwide. (wikipedia.org)
  • Three categories of trinucleotide repeat disorders and related microsatellite (4, 5, or 6 repeats) disorders are described by Boivin and Charlet-Berguerand. (wikipedia.org)
  • The second main category of trinucleotide repeat disorders and related microsatellite disorders involves a toxic RNA gain of function mechanism. (wikipedia.org)
  • The third main category of trinucleotide repeat disorders and related microsatellite disorders is due to the translation of repeat sequenced into pathogenic proteins containing a stretch of repeated amino acids. (wikipedia.org)
  • Preliminary results indicate that high quality trinucleotide microsatellite markers can be developed in wheat. (usda.gov)
  • We found that replication fork stalling was dependent on the integrity of the mismatch-repair system, especially the Msh2p-Msh6p complex, suggesting that direct interaction of MMR proteins with secondary structures formed by trinucleotide repeats in vivo, triggers replication fork pauses. (edu.sa)
  • Our results unravel two new roles for mismatch-repair proteins: stabilization of heteroduplex regions and transient blocking of replication forks passing through such repeats. (edu.sa)
  • Additionally, we am interested in the molecular genetics and experimental treatment of the trinucleotide repeat disorder myotonic dystrophy (DM1). (rochester.edu)
  • We also show by chromatin immunoprecipitation that Msh2p is enriched at trinucleotide repeat tracts, in both stable and unstable orientations, this enrichment being dependent on MSH3 and MSH6. (edu.sa)
  • In the third patient in the cerebellar ataxia group, we identified a novel 21-base duplication mutation near 22 CAG repeats (c.432_452dup). (nih.gov)
  • Individuals with pre-mutation alleles have 59-230 repeats whereas individuals with intermediate sized alleles ("gray zone" alleles) have 41-58 repeats, broadly defined. (uab.edu)
  • Molecular genetics of hereditary spinocerebellar ataxia: mutation analysis of spinocerebellar ataxia genes and CAG/CTG repeat expansion detection in 225 Italian families. (cdc.gov)
  • Researchers believe that a fragment of the androgen receptor protein containing the CAG repeats accumulates within these cells and interferes with normal cell functions. (medlineplus.gov)
  • The decision to rescreen a patient should be undertaken only with the guidance of a genetics professional who can best assess the incremental benefit of repeat testing for additional mutations. (acog.org)
  • To provide the clinical diagnostics community with accurate protocols and measurements for the detection of genetic disorders, we have established a quantitative a quantitative measurement program for trinucleotide repeats associated with human disease. (nist.gov)
  • Expansion of trinucleotide repeats , such as CAG that encodes for polyglutamine, is associated with a number of neurodegenerative disorders. (the-scientist.com)
  • A simple method for the detection of neurologic disorders associated with CAG repeat expansion using PCR-microtiter plate hybridization. (cdc.gov)
  • Correlation between the onset age of Huntington's disease and length of the trinucleotide repeat in IT-15. (nature.com)
  • Relationship between trinucleotide repeat expansion and phenotypic variation in Huntington's disease. (nature.com)
  • Preventing polyglutamine repeat oligomerization reverses symptoms of Huntington's chorea. (the-scientist.com)
  • However, the frequency of occurrence of any one particular repeat sequence disorder varies greatly by ethnic group and geographic location. (wikipedia.org)
  • The repeat sizes were verified by DNA sequence analyzes. (nist.gov)
  • Huntington disease (HD), an autosomal dominant, progressive neurodegenerative disorder, is caused by an expanded CAG repeat sequence leading to an increase in the number of glutamine residues in the encoded protein 1 . (nature.com)
  • The Global Repeat Map (GRM) algorithm is a convenient computational tool to determine consensus repeat units and their exact size within a given genomic sequence, both of monomeric and higher-order (HOR) type. (srce.hr)
  • Although GP60 sequence typing had very low dis- (variable numbers and forms of a repeating sequence of 3 criminatory power for UK C. hominis isolates, our fi ndings nucleotides coding for the amino acid serine) and the hy- are in agreement with previous fi ndings based on multiple pervariable downstream region ( 5 ). (cdc.gov)
  • With increasing repeat number, the protein changes conformation and becomes increasingly prone to aggregation 11 , suggesting important functional correlations between repeat length and pathology. (nature.com)
  • Glunčić M, Rosandić M, Jelovina D, Dekanić K, Vlahović I, Paar V. Global Repeat Map Method for Higher Order Repeat Alpha Satellites in Human and Chimpanzee Genomes (Build 37.2 Assembly). (srce.hr)
  • Exon 1 contains a CAG trinucleotide repeat that encodes the amino acid glutamine, followed by another repeat that encodes proline. (jci.org)
  • Our objectives were to determine the abundance of trinucleotide microsatellites and the rate at which they can be developed into informative markers. (usda.gov)
  • A genomic library from Chinese Spring' (CS) was screened with 5 trinucleotide probes and about 1.1% of the clones contained microsatellites. (usda.gov)
  • Individuals with expanded repeats developed balance and gait disturbances at 15 to 60. (lu.se)
  • Individuals with expanded repeats developed balance and gait disturbances at 15 to 60 years of age and had sensory neuropathy and slow saccades. (lu.se)
  • In unaffected individuals, there are 10-34 CAG repeats. (jci.org)
  • The discovery that trinucleotide repeats could expand during intergenerational transmission and could cause disease was the first evidence that not all disease-causing mutations are stably transmitted from parent to offspring. (wikipedia.org)
  • Genetic and clinical analysis of spinocerebellar ataxia type 8 repeat expansion in Italy. (cdc.gov)
  • Trinucleotide repeat diseases. (nih.gov)
  • Anticipation was observed in all families and correlated with different repeat lengths determined through long-read sequencing in two family members. (lu.se)
  • The epigenetic alterations and their effects are described more fully by Barbé and Finkbeiner These authors cite evidence that the age at which an individual begins to experience symptoms, as well as the severity of disease, is determined both by the size of the repeat and the epigenetic state within the repeat and around the repeat. (wikipedia.org)
  • Dissecting the epidemiology of a trinucleotide repeat disease - example of FRDA in Finland. (cdc.gov)
  • However, comparing the HD76 neurons with the previously described low-repeat HD models, we have demonstrated that the severity of calcium signaling alterations does not depend on the length of the polyglutamine tract of the mutant huntingtin. (frontiersin.org)
  • Non-expanded alleles carried one or more interruptions within the repeat. (lu.se)
  • Instead of the typical 10 to 36 repeats, CAG is repeated from 38 to more than 60 times in people with this disorder. (medlineplus.gov)
  • Some carriers, during the formation of eggs or sperm, may give rise to higher levels of repetition of the repeat they carry. (wikipedia.org)
  • Both roles may involve direct interactions between MMR proteins and secondary structures formed by trinucleotide repeat tracts, although indirect interactions may not be formally excluded. (edu.sa)
  • Two patients in the chronic neuropathy group had a full repeat expansion or an intermediate expansion (39 or 32 repeats), without limb ataxia. (nih.gov)
  • Figure 1: Typical GeneScan traces for sizing of the CAG repeat from heart and striatal tissue of Msh2 -/- and Msh2 +/+ mice. (nature.com)
  • Figure 2: Distribution of CAG repeats before and after the major GeneScan peak for various tissues from Msh2 -/- and Msh2 +/+ mice. (nature.com)
  • Alpha satellites are tandemly repeated sequences found in all human centromeres. (srce.hr)
  • We found PCR-amplified products potentially corresponding to expanded CAG repeats in four patients. (nih.gov)
  • Patients with expanded CAG repeats can exhibit a neuropathy-dominant phenotype not described previously. (nih.gov)
  • Since FXS cannot always be identified by cytogenetic analysis, molecular testing of the fragile X mental retardation 1 CGG repeat was performed in 440 samples. (wjgnet.com)
  • Many regions of the genome (exons, introns, intergenic regions) normally contain trinucleotide sequences, or repeated sequences of one particular nucleotide, or sequences of 2, 4, 5 or 6 nucleotides. (wikipedia.org)
  • Polymerase chain reaction analysis is used as a first tier test to define the repeat size. (uab.edu)
  • Polymerase chain reaction analysis is used to further define the repeat number more precisely. (uab.edu)