Familial congenital non-immune hydrops, chylothorax, and pulmonary lymphangiectasia.

Pulmonary lymphangiectasia is an uncommon congenital anomaly, and familial occurrence has rarely been reported. We report on two sibs with bilateral pleural effusion/chylothorax and hydrops who died neonatally. One sib required prenatal intrauterine hemithoracic drainage. Autopsy confirmed congenital pulmonary lymphangiectasia (CPL) histologically in the first case. Hydrops, characterized as subcutaneous edema and effusions in two or more body cavities, may be due to a variety of factors, but the co-occurrence of CPL in one of these sibs, although rare, supports the notion that chylothorax and hydrops may be caused by structural lesions of lymph channels. Although most cases of CPL are sporadic, the reported sibs support autosomal recessive inheritance, with intrafamilial variability of a lymphatic disorder on a genetic basis. Mutations in vascular endothelial growth factor receptor-3 (VEGFR3) in families with Milroy disease, mutations of FOXC2 in the lymphedema-distichiasis syndrome, and fatal chylothorax in alpha9-deficient mice are potential candidate genes.