• Short tandem repeats (STRs) compose approximately 3% of the genome, and mutations at STR loci have been linked to dozens of human diseases including amyotrophic lateral sclerosis, Friedreich ataxia, Huntington disease, and fragile X syndrome. (biomedcentral.com)
  • We hypothesize that there might be at least three types of autism susceptibility genes/mutations that can be (i) specific to an individual patient or family, (ii) in a genetically isolated sub-population and (iii) a common factor shared amongst different populations. (neurotransmitter.net)
  • The genes/mutations could act alone or interact with other genetic and/or epigenetic or environmental factors, causing autism or related disorders. (neurotransmitter.net)
  • During expansion mutations, single-stranded DNAs (ssDNAs) form slipped-DNAs. (bvsalud.org)
  • Some of these tools are designed to detect STR expansions at disease-related loci, while others detect expansions and contractions of STRs genome-wide but are constrained by sequencing read length and the STR motif size. (biomedcentral.com)
  • This review emphasizes the potential of analysing chromosomal rearrangements as a means to rapidly define candidate disease loci for further investigation. (neurotransmitter.net)
  • Discovery of disease-causing repeat expansion loci accelerated through technological advances in DNA sequencing and computational analyses. (bvsalud.org)
  • Between 2019 and 2021, 17 new disease-causing TR expansions were reported, totaling 63 TR loci (>69 diseases), with a likelihood of more discoveries, and in more organisms. (bvsalud.org)
  • Copy number variation (CNV) is a phenomenon in which sections of the genome are repeated and the number of repeats in the genome varies between individuals. (wikipedia.org)
  • Approximately two-thirds of the entire human genome may be composed of repeats and 4.8-9.5% of the human genome can be classified as copy number variations. (wikipedia.org)
  • On the other hand, a variable number of repeats of entire genes is less commonly identified in the genome. (wikipedia.org)
  • Although it was originally detected by fluorescent in situ hybridization and microsatellite analysis that copy number repeats are localized to regions that are highly repetitive such as telomeres, centromeres, and heterochromatin, recent genome-wide studies have concluded otherwise. (wikipedia.org)
  • in contrast to simple family structures reported for a variety of angiosperm nsltp genes, the putative pine nsltp gene is a member of a complex family. (liverpool.ac.uk)
  • Expansions, contractions, and somatic length variations of TRs can have clinical/biological consequences. (bvsalud.org)
  • Inducing contractions of expanded repeats can be a means to treat DRPLA, for which no disease-modifying or curative therapies exist at present. (bvsalud.org)
  • of tandem repeats within their genomes [6, 17]. (scirp.org)
  • Repeat motifs may not be present in current reference genomes but will be in forthcoming gapless long-read references. (bvsalud.org)
  • We searched the expressed sequence tag databank for reiterated trinucleotides and selected EST00493 (D2S196E) with 14 tandem ACA triplets as a potentially polymorphic locus. (scite.ai)
  • At a given locus, repeat motif sequence purity can vary with consequence. (bvsalud.org)
  • Our survey found cytogenetically visible chromosomal anomalies in ~7.4% (129/1749) of autistic patients documented as well as several sub-microscopic variants. (neurotransmitter.net)
  • The first stage involved identifying, in unrelated subjects showing linkage to 2q24-q33, genetic variants in exons and flanking sequence within candidate genes and comparing the frequency of the variants between autistic and unrelated nonautistic subjects. (neurotransmitter.net)
  • Short tandem repeats (STRs), or microsatellites, are 1-6 base pair (bp) motifs of repeating units of DNA. (biomedcentral.com)
  • It was thought that these large-scale chromosomal rearrangements give rise to normal variation and genetic diseases, including copy number variations. (wikipedia.org)
  • Size variation was readily detected, with four common alleles containing 12-15 repeats. (scite.ai)
  • multiple alleles at qtl allow the examination of interaction among alleles at qtl (deviation from additive gene action). (liverpool.ac.uk)
  • One of the most well known examples of a short copy number variation is the trinucleotide repeat of the CAG base pairs in the huntingtin gene responsible for the neurological disorder Huntington's disease. (wikipedia.org)
  • Long expansions of transcribed trinucleotide microsatellites have been etiologically associated with some neurological diseases. (scite.ai)
  • Indeed, mutation detection enhancement gel electrophoresis of mixed PCR products from cloned haplotypes revealed 24 distinct heteroduplex patterns for the six possible trinucleotide heterozygotes. (scite.ai)
  • from the mutation of a single gene. (scirp.org)
  • METHOD: Mutation screening of positional candidate genes was performed in two stages. (neurotransmitter.net)
  • Expansions of gene-specific DNA tandem repeats (TRs), first described in 1991 as a disease-causing mutation in humans, are now known to cause >60 phenotypes, not just disease, and not only in humans. (bvsalud.org)
  • The observation of heteroduplex patterns in non-denaturing polyacrylamide gel electrophoresis (instead of the more commonly used denaturing gels) can thus be utilized to increase the informativeness of microsatellite polymorphisms by unraveling otherwise cryptic sequence variation. (scite.ai)
  • In addition, if these trinucleotide repeats are in the same reading frame in the coding portion of a gene, it may lead to a long chain of the same amino acid, possibly creating protein aggregates in the cell, and if these short repeats fall into the non-coding portion of the gene, it may affect gene expression and regulation. (wikipedia.org)
  • lipid transfer protein genes of loblolly pine are members of a complex gene family. (liverpool.ac.uk)
  • For this particular case, once the CAG trinucleotide repeats more than 36 times in a trinucleotide repeat expansion, Huntington's disease will likely develop in the individual and it will likely be inherited by his or her offspring. (wikipedia.org)
  • The number of repeats of the CAG trinucleotide is inversely correlated with the age of onset of Huntington's disease. (wikipedia.org)
  • Previously, we characterized a small molecule, naphthyridine-azaquinolone (NA), which binds to CAG slip-out structures and induces repeat contraction in Huntington's disease mice. (bvsalud.org)
  • One example of a whole gene repeat is the alpha-amylase 1 gene (AMY1) that encodes alpha-amylase which has a significant copy number variation between different populations with different diets. (wikipedia.org)
  • Repeats of entire genes has immediate effects on expression of that particular gene, and the fact that the copy number variation of the AMY1 gene has been related to diet is a remarkable example of recent human evolutionary adaptation. (wikipedia.org)
  • Negative association findings and research involving the serotonin transporter gene, FMR1, RELN, WNT2, HOXA1, and HOXB1 genes may be found elsewhere on this site . (neurotransmitter.net)
  • These findings suggest a functional interplay between the two RPAs where Alt-RPA may antagonistically offset RPA's suppression of disease-associated repeat expansions, which may extend to other DNA processes. (bvsalud.org)
  • Expansions of repeat DNA tracts cause >70 diseases, and ongoing expansions in brains exacerbate disease. (bvsalud.org)
  • Repeat diseases show atypical clinical features, genetic anticipation, and multiple and partially penetrant phenotypes among family members. (bvsalud.org)
  • genetic analysis of cinnamyl alcohol dehydrogenase in loblolly pine: single gene inheritance, molecular characterization and evolution. (liverpool.ac.uk)
  • Copy number variations can be generally categorized into two main groups: short repeats and long repeats. (wikipedia.org)
  • The short repeat size of these copy number variations lends itself to errors in the polymerase as these repeated regions are prone to misrecognition by the polymerase and replicated regions may be replicated again, leading to extra copies of the repeat. (wikipedia.org)
  • control of cad gene expression could involve either differential regulation of more than one cad gene or, alternatively combinatorial regulation of a single cad gene. (liverpool.ac.uk)
  • Short repeats include mainly dinucleotide repeats (two repeating nucleotides e.g. (wikipedia.org)
  • These types of short repeats are often thought to be due to errors in polymerase activity during replication including polymerase slippage, template switching, and fork switching which will be discussed in detail later. (wikipedia.org)
  • Long repeats include repeats of entire genes. (wikipedia.org)
  • These hotspot regions were defined to be regions containing long repeats that are 90-100% similar known as segmental duplications either tandem or interspersed and most importantly, these hotspot regions have an increased rate of chromosomal rearrangement. (wikipedia.org)
  • Here, we demonstrate that long-term intracerebroventricular infusion of NA leads to repeat contraction, reductions in mutant ATN1 aggregation, and improved motor phenotype in a murine model of DRPLA. (bvsalud.org)
  • In the present study, genes across the 2q24-q33 interval were analyzed to identify an autism susceptibility gene in this region. (neurotransmitter.net)
  • Two single nucleotide polymorphisms (SNPs) that showed evidence for divergent distribution between autistic and nonautistic subjects were identified, both within SLC25A12, a gene encoding the mitochondrial aspartate/glutamate carrier (AGC1). (neurotransmitter.net)
  • Repeat motif size can be a single nucleotide to kilobases/unit. (bvsalud.org)
  • Although the specific mechanism that allows the AMY1 gene to increase or decrease its copy number is still a topic of debate, some hypotheses suggest that the non-homologous end joining or the microhomology-mediated end joining is likely responsible for these whole gene repeats. (wikipedia.org)
  • RPA enhances in vitro melting, FAN1 excision, and repair of slipped-CAGs and protects against CAG expansions in human cells. (bvsalud.org)
  • The expanded CAG repeats are unstable, and ongoing repeat expansions contribute to disease onset, progression, and severity. (bvsalud.org)
  • Participants from the baseline of the BambuĂ­ Health Aging Study whose ApoE genes had been genotyped were selected for this study (N = 1406, aged 60-95 years). (scite.ai)