Résumé
To identify novel genetic bases of early-onsetepithelial ovarian tumors, we used the trio exome sequencing strategy in a patient without familial history of cancerwho presented metastatic serous ovarian adenocarcinomasat 21 years of age. We identified a single de novo mutation(c.1157A>G/p.Asn386Ser) within the INHBA gene encoding the βA-subunit of inhibins/activins, which play akey role in ovarian development. In vitro, this mutation alters the ratio of secreted activins and inhibins. In a secondpatient with early-onset serous borderline papillary cystadenoma, we identified an unreported germline mutation(c.179G>T/p.Arg60Leu) of the INHA gene encoding theα-subunit, the partner of the βA-subunit. This mutationalso alters the secreted activin/inhibin ratio, by disruptingboth inhibin A and inhibin B biosynthesis. In a cohort of62 cases, we detected an additional unreported germlinemutation of the INHBA gene (c.839G>A/p.Gly280Glu).Our results strongly suggest that inhibin mutations contribute to the genetic determinism of epithelial ovariantumors.