A hydatidiform mole is an abnormal pregnancy characterized by hydropic placental villi, trophoblastic hyperplasia, and poor fetal development. Familial recurrent hydatidiform mole is an autosomal recessive condition in which women experience recurrent pregnancy losses, predominantly complete hydatidiform mole (CHM). However, unlike sporadic CHMs, which are androgenetic with 2 paternal chromosome complements, CHMs associated with familial recurrence are genetically biparental in origin with both a maternal and a paternal contribution to the genome. Other pregnancy losses in this condition include partial hydatidiform mole, stillbirths, ectopic pregnancies, early neonatal deaths, and miscarriages, some of which may be undiagnosed molar pregnancies. Normal pregnancies are extremely rare in families with this condition (summary by Fallahian et al., 2013).
Genetic Heterogeneity of Recurrent Hydatidiform Mole
Another form of recurrent complete hydatidiform mole (HYDM2; 614293) is caused by mutation in the KHDC3L gene (611687) on chromosome 6q13. HYDM3 (618431) is caused by mutation in the MEI1 gene (608797) on chromosome 22q13. HYDM4 (618432) is caused by mutation in the C11ORF80 gene (616109) on chromosome 11q13. [from
OMIM]