The genetics of hydatidiform moles: new lights on an ancient disease

Hydatidiform mole (HM) is a human pregnancy with no embryo but cystic degeneration of chorionic villi. The common form of this condition occurs in 1 in every 1500 pregnancies in western societies and at a higher incidence in some geographic regions and populations. Recurrent moles account for 2% of all molar cases and a few of them occur in more than one family member. By studying a familial form of recurrent moles, a recessive maternal locus responsible for this condition was mapped to 19q13.4 and causative mutations identified. The defective protein, NALP7, is part of the CATERPILLAR protein family with roles in pathogen-induced inflammation and apoptosis. The exact role of NALP7 in the pathophysiology of molar pregnancies is unknown yet. NALP7 could have a role either in oogenesis or in the endometrium during trophoblast invasion and decidualization. In this review, we outlined recent advances in the field of HMs and reviewed the literature in the light of the new data.