Association between mutations in the FMR1 gene and ovarian dysfunction in Brazilian patients

OBJECTIVE: Our study aimed to identify mutations in the FMR1 gene in a group of Brazilian women diagnosed with primary ovarian insufficiency (POI). METHODS: This cross-sectional study included patients aged under 40 years with confirmed POI from a convenience sample of patients seen from June 2017 to December 2018 at a University Hospital in Curitiba, Brazil. Genomic DNA was extracted and analyzed using FragilEase(tm) PCR kits (PerkinElmer), a commercially available test that enables the quantification of CGG trinucleotide repeat expansions in the FMR1 gene. RESULTS: A total of 52 patients with an average age of 35.8±3.97 years were included. Fifty (96.1%) had normal alleles with 18 to 43 CGG repeats. The most frequent CGG-repeat sizes were 28 and 30. Two patients (3.8%) presented mutations in the FMR1 gene. The first had alleles with 19/97 CGG repeats, was categorized as a premutation carrier for FXS, and had a son with cognitive impairment. The second had alleles with 21/45 CGG repeats and was described as belonging to the gray zone. CONCLUSIONS: In our study, 3.8% of the females with POI had mutations in the FMR1 gene. The most frequent allele sizes were 28 and 30 CGG repeats.