A study on the role of FMR1 CGG trinucleotide repeats in Jordanian poor ovarian responders

Gene. 2021 Jan 30:767:145174. doi: 10.1016/j.gene.2020.145174. Epub 2020 Sep 30.

Abstract

The expansion of trinucleotide CGG repeats in the promoter of fragile X mental retardation 1 (FMR1) gene is associated with fragile X and fragile X associated tremor/ataxia syndromes. While the expansion of CGG repeats has been associated with such neuro/psychiatric diseases, the contraction of CGG repeats has been recently suggested as an indication of ovarian dysfunction. This study aimed to evaluate a possible association of the short CGG repeats with poor ovarian responders (POR) and to test for a possible correlation between the CGG size and different known markers of the ovarian reserve, namely FSH, AMH, and the number of retrieved oocytes from Jordanian females. We found a significant difference between the CGG median allele size between the cases and the controls (p < 0.001), where poor ovarian responders had shorter CGG repeats compared to the healthy controls. Also, females with alleles <26 had twice the odds to be presented in the POR compared to the controls. However, we did not find a significant correlation between CGG sizes and the markers of ovarian reserve. We conclude that although low CGG repeats appear to be linked to POR, the clinical utility of FMR1 for predicting ovarian response needs further investigation.

Keywords: Assisted reproductive technology; CGG repeats; FMR1; Female infertility; Poor ovarian response.

MeSH terms

  • Adult
  • Alleles
  • Anti-Mullerian Hormone / genetics
  • Ataxia
  • Female
  • Follicle Stimulating Hormone / genetics
  • Fragile X Mental Retardation Protein / genetics*
  • Fragile X Mental Retardation Protein / metabolism
  • Fragile X Syndrome
  • Gene Frequency / genetics
  • Humans
  • Jordan / epidemiology
  • Ovarian Reserve / genetics*
  • Ovarian Reserve / physiology
  • Ovary / metabolism
  • Primary Ovarian Insufficiency / genetics
  • Primary Ovarian Insufficiency / physiopathology
  • Promoter Regions, Genetic / genetics
  • Tremor
  • Trinucleotide Repeat Expansion
  • Trinucleotide Repeats / genetics*

Substances

  • FMR1 protein, human
  • Fragile X Mental Retardation Protein
  • Anti-Mullerian Hormone
  • Follicle Stimulating Hormone

Supplementary concepts

  • Fragile X Tremor Ataxia Syndrome