Premutations of FMR1 CGG repeats are not related to idiopathic premature ovarian failure in Iranian patients: A case control study

Abstract

Premature ovarian failure (POF) is a reproductive disease which affects 1 in 100 under 40 years women. FMR1 premutation carriers of CGG repeats are supposed to be at increased risk for POF. We have examined the 5'UTR region of the gene to find any association between the repeat size and the disease etiology in Iranian population. 30 women with early idiopathic POF and 30 fertile control women were selected. We used triplet repeat primed PCR (TP PCR) assay and gene-specific primers to amplify the CpG Island of FMR1 gene promoter region. The amplification results were analyzed by capillary electrophoresis and Gene Marker software. Among 30 patients, two had intermediate repeat size, one had premutation and the rest had CGG repeat of the normal range. Two of controls had intermediate repeats and none had a premutation. Two groups had significant differences in the repeat number average (p = 0.007) and in the average length of the smallest allele (p < 0.001), but had no promising difference in average length of the longest allele (p = 0.453). Although the two groups showed a significant difference in the length of alleles, their length was within normal range. Perhaps the polymorphism, in connection with the genome's entire network, has been involved in the development of the disease, or there has been a fundamentally different mechanism for the disease in Iranian population. A larger number of Iranian POF patients should be investigated for any probable relationship between the CGG triplet repeat length and the etiology of the disease.

Keywords: Biomarker; CGG repeat; FMR1; Idiopathic POF; Premature ovarian failure (POF).