Open AccessAn n-allele model for progressive amplification in the FMR1 locus.
Author(s) -
Adam P. Morris,
N. E. Morton,
Amanda Collins,
James Macpherson,
David L. Nelson,
Stephanie L. Sherman
Publication year - 1995
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.92.11.4833
Subject(s) - fmr1 , allele , locus (genetics) , genetics , fragile x syndrome , biology , allele frequency , population , gene , medicine , environmental health
An n-allele model is developed for the FMR1 locus, which causes the fragile X syndrome, where n is the number of triplet repeats in the first exon. Frequencies in the general population and in index families are used to generate an n to n + delta transition matrix that predicts specific risks in satisfactory agreement with observation. However, until sequencing distinguishes between stable and unstable alleles with the same value of n, it is premature to infer whether allelic frequencies at the FMR1 locus are at equilibrium or, as some have suggested, are evolving toward higher frequencies of the pathogenic allele.