Genetics and Epigenetics of Hydatidiform Moles

Abstract

Advanced articleArticle Contents • Introduction • Genotypic Types of HM • Genes Responsible for RHM • Functions of NLRP7 and KHDC3L • Imprinting • Oocyte Cytoskeleton • Concluding Remarks • Acknowledgements Online posting date: 16 th January 2017A hydatidiform mole (HM) is an abnormal human pregnancy characterised by absence of, or abnormal, embryonic development, excessive trophoblastic proliferation and hydropic degeneration of placental villi. The common types of moles are sporadic, not recurrent, and affect 1 in 1000 pregnancies in western countries. HM may recur in the same patient, which is referred to as recurrent HM (RHM), and indicates that the patient is genetically susceptible to HM. Through the examination of rare familial cases of RHM, two maternal-effect genes, NLRP7 and KHDC3L, responsible for this condition have been identified. Pathogenic variants in these genes appear to impair imprinting establishment during oogenesis. Herein, we review current knowledge on the genetics and epigenetics of RHM, and highlight the benefits of testing patients for pathogenic variants in the known genes.