Mutant Cohesin in Premature Ovarian Failure

Premature ovarian failure is a major cause of female infertility. The genetic causes of this disorder remain unknown in most patients. Using whole-exome sequence analysis of a large consanguineous family with inherited premature ovarian failure, we identified a homozygous 1-bp deletion inducing a frameshift mutation in STAG3 on chromosome 7. STAG3 encodes a meiosis-specific subunit of the cohesin ring, which ensures correct sister chromatid cohesion. Female mice devoid of Stag3 are sterile, and their fetal oocytes are arrested at early prophase I, leading to oocyte depletion at 1 week of age. Few genes have been implicated in sporadic premature ovarian failure. This study implicates STAG3, which encodes a cohesin, a protein that mediates chromosome pairing during meiosis. Premature ovarian failure, the end point of primary ovarian insufficiency, affects approximately 1% of women worldwide. Patients with premature ovarian failure present with at least a 6-month history of amenorrhea and elevated plasma levels of follicle-stimulating hormone (>40 mIU per milliliter). The disorder can result from premature depletion of the follicle pool, follicular atresia, follicle growth arrest, or ovarian dysgenesis. Although a majority of cases are idiopathic, premature ovarian failure can be caused by infectious agents, chemotherapy, pelvic surgery, autoimmune disease, environmental factors, or genetic conditions.(1) The disorder is observed in syndromic diseases for example, Turner's syndrome and BPES ...