Abstract
Premature or primary ovarian insufficiency (POI) affects approximately 1% of women and can be due to a variety of causes. Genetic causes include syndromic and non-syndromic POI. There are several promising candidate genes for whom a clear Mendelian association with non-syndromic POI has not yet been conclusively established, including GDF9. GDF9 is an oocyte-secreted factor and is part of the TGF-beta superfamily of morphogens. It has an important role in follicular development and granulosa cell maturation. We report the case of two siblings with primary ovarian insufficiency (POI) and a homozygous truncating variant in GDF9 (c.604C>T; p.(Gln202*). This report helps establish a clear gene-disease association between GDF9 and POI and argues for routine evaluation for GDF9 variants in patients undergoing genomic investigation for POI.