['Primary ovarian insufficiency (POI) is a disorder affecting approximately 1% of women under the age of 40 years. NR5A1 (SF-1) mutations have been recently reported in association with POI.', 'Our objective was to evaluate the frequency and functional impact of NR5A1 variants in POI.', 'One hundred eighty patients diagnosed with idiopathic POI were screened for NR5A1 mutations and functional analysis was performed for the identified variants. The DNA-binding capacity of the variants was evaluated by means of EMSA, while their transcriptional activity was assessed using luciferase reporter assays.', 'Sequencing the NR5A1 gene revealed 4 missense variants in 3 patients. These patients were aged 20, 25, and 33 years at diagnosis and presented with secondary amenorrhea. None of them presented a syndromic form, although 2 had a familial history of POI. The functional analysis carried out for these missense variants showed no significant difference in DNA binding capacity or in transcriptional activity compared to wild-type NR5A1.'] Are nR5A1 ( SF-1 ) mutations a major cause of primary ovarian insufficiency?