Deletion and Insertion Mutations in Short Tandem Repeats in the Coding Regions of Human Genes

1995 ◽  
Vol 3 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Ariel Darvasi ◽  
Batsheva Kerem
2016 ◽  
Author(s):  
◽  
Christine Queitsch

ABSTRACTShort tandem repeats are hypervariable genetic elements that occur frequently in coding regions. Their high mutation rate readily generates genetic variation contributing to adaptive evolution and human diseases. We recently proposed that short tandem repeats are likely to engage in epistasis because they are well-positioned to compensate for genetic variation arising at other loci due to their high mutation rate. We previously reported that natural ELF3 polyglutamine variants cause reciprocal genetic incompatibilities in two divergent Arabidopsis thaliana backgrounds. Here, we dissected the genetic architecture of this incompatibility and used a yeast two-hybrid strategy to identify proteins whose physical interactions with ELF3 were modulated by polyglutamine tract length. Using these two orthogonal approaches, we identify specific genetic interactions and physical mechanisms by which the ELF3 polyglutamine tract may mediate the observed genetic incompatibilities. Our work elucidates how short tandem repeat variation, which is generally underascertained in population-scale sequencing, can contribute to phenotypic variation. Furthermore, our results support our proposal that highly variable STR loci can contribute disproportionately to the epistatic component of heritability.


2000 ◽  
Vol 76 (3) ◽  
pp. 227-236 ◽  
Author(s):  
YONG ZHU ◽  
JOAN E. STRASSMANN ◽  
DAVID C. QUELLER

This paper uses data from the Human Gene Mutation Database to contrast two hypotheses for the origin of short DNA repeats: substitutions and insertions that duplicate adjacent sequences. Because substitutions are much more common than insertions, they are the dominant source of new 2-repeat loci. Insertions are rarer, but over 70% of the 2–4 base insertion mutations are duplications of adjacent sequences, and over half of these generate new repeat regions. Insertions contribute fewer new repeat loci than substitutions, but their relative importance increases rapidly with repeat number so that all new 4–5-repeat mutations come from insertions, as do all 3-repeat mutations of tetranucleotide repeats. This suggests that the process of repeat duplication that dominates microsatellite evolution at high repeat numbers is also important very early in microsatellite evolution. This result sheds light on the puzzle of the origin of short tandem repeats. It also suggests that most short insertion mutations derive from a slippage-like process during replication.


1997 ◽  
Vol 45 (3) ◽  
pp. 265-270 ◽  
Author(s):  
Anna Pérez-Lezaun ◽  
Francesc Calafell ◽  
Mark Seielstad ◽  
Eva Mateu ◽  
David Comas ◽  
...  

Genetics ◽  
2000 ◽  
Vol 155 (4) ◽  
pp. 1973-1980
Author(s):  
Jinko Graham ◽  
James Curran ◽  
B S Weir

Abstract Modern forensic DNA profiles are constructed using microsatellites, short tandem repeats of 2–5 bases. In the absence of genetic data on a crime-specific subpopulation, one tool for evaluating profile evidence is the match probability. The match probability is the conditional probability that a random person would have the profile of interest given that the suspect has it and that these people are different members of the same subpopulation. One issue in evaluating the match probability is population differentiation, which can induce coancestry among subpopulation members. Forensic assessments that ignore coancestry typically overstate the strength of evidence against the suspect. Theory has been developed to account for coancestry; assumptions include a steady-state population and a mutation model in which the allelic state after a mutation event is independent of the prior state. Under these assumptions, the joint allelic probabilities within a subpopulation may be approximated by the moments of a Dirichlet distribution. We investigate the adequacy of this approximation for profiled loci that mutate according to a generalized stepwise model. Simulations suggest that the Dirichlet theory can still overstate the evidence against a suspect with a common microsatellite genotype. However, Dirichlet-based estimators were less biased than the product-rule estimator, which ignores coancestry.


2019 ◽  
Vol 108 (2) ◽  
pp. e115-e117
Author(s):  
Kelly Brown ◽  
Robert Homer ◽  
Marina Baine ◽  
Justin D. Blasberg

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