Clinical and Genetic Investigation of Premature Ovarian Insufficiency Cases from Turkey

Objective Premature ovarian insufficiency is a lack of ovarian functions in patients younger than 40 years old. Genetic causes leading to accelerated follicle depletion may result in premature ovarian insufficiency. We aimed to determine genetic etiology of nonsyndromic premature ovarian insufficiency cases from Turkey. Materials and methods We analyzed 86 nonsyndromic premature ovarian insufficiency cases and 26 matched control female participants. Participants have been investigated in cytogenetic analysis followed by FMR1 repeat size expansions and search of variants for nine premature ovarian insufficiency-associated genes. Results Four cases had a structural cytogenetic abnormality. Two cases revealed with premutation size FMR1 triplet repeat expansion. Four cases carried variants in which two were very rare in FSHR and PDPK1, and three were novel in NR5A1, PDPK1, and POF1B genes. Six novel variants have been identified in NOBOX, NR5A1, POF1B, and PDPK1 in control population assigned to be benign alterations. Conclusion Mosaicism of sex chromosomes was responsible in 4.6% and FMR1 premutation in 2.4% of premature ovarian insufficiency cases, while the association of premature ovarian insufficiency-related genes was found very subtle. Novel variants in NR5A1, PDPK1, and POF1B may necessitate further evaluation for their association with premature ovarian insufficiency via functional studies.