New STAG3 gene variant as a cause of premature ovarian insufficiency

Objectives: To describe a case of ovarian failure secondary to a homozygous pathogenic variant in the STAG3 gene not previously reported. Materials and Methods: A 16-year-old patient with primary amenorrhea and absence of secondary sexual characteristics, with documented autoimmune hypothyroidism, poor genital and gonadal streak development which prompted the performance of clinical exome sequencing. A homozygous pathogenic variant not previously reported in the STAG3 gene, which has been associated with premature ovarian insufficiency (POI), was identified. Conclusions: In this case, clinical exome sequencing was key for identifying a STAG gene abnormality, probably associated with POI and long term prognosis for the patient. A new pathogenic variant c.2773delT; p.Ser925Profs*6 of the STAG3 gene associated with POI was established.