The length of Fragile X premutations are directly associated to the degree of ovarian function. This study highlights more details of a genetic cause fro premature ovarian failure (POF) or as some like to call it premature ovarian insufficiency (POI).
This study suggests a spectrum of ovarian dysfunction
Fragile X is a genetic condition in which the X chromosome carries a variable number of repeating trinucleotides (CGG). The CGG repeats make the chromosome constrict and thus look fragile under the microscope. Fragile X is a leading genetic causes of mental retardation in the male.
Association of FMR1 repeat size with ovarian dysfunction
A.K. Sullivan1, M. Marcus1, M.P. Epstein1, E.G. Allen1, A.E. Anido1, J.J. Paquin1, M. Yadav-Shah1 and S.L. Sherman1,2
1 Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
2 To whom correspondence should be addressed at: Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Suite 301, Atlanta, GA 30322, USA. Email: firstname.lastname@example.org
BACKGROUND: Women who carry the FMR1 premutation allele have a significantly increased risk for ovarian dysfunction. We hypothesize that molecular characteristics of the FMR1 gene may explain this increased risk.
METHODS: Thus, we examined the effect of FMR1 CGG repeat size and related factors on measures of ovarian dysfunction using data from 507 women with a wide range of repeat sizes.
RESULTS AND CONCLUSIONS: We found a significant positive association of repeat size with ovarian dysfunction, but have preliminary evidence that this relationship is non-linear. We suggest that FMR1 repeat size in the lower range (<80 repeats) contributes to the variation in age at menopause; thus, FMR1 could be considered a quantitative trait locus. More importantly, when repeat size exceeds this threshold, the increase in risk for ovarian dysfunction is clinically significant. Intriguingly, this risk appears to plateau, or perhaps decrease, among women with very high repeats (≥100 repeats).