Abnormality of the kidney renal hypodysplasia/aplasia 3 Hannah McLaren OMIM:617805 RHDA3 Renal hypodysplasia/aplasia 3 (RHDA3) is an autosomal dominant disorder characterized by abnormal kidney development beginning in utero. The phenotype is highly variable, even within families, and there is evidence for incomplete penetrance. Some affected individuals have bilateral renal agenesis, which is usually fatal in utero or in the perinatal period, whereas others may have unilateral agenesis that is compatible with life, or milder manifestations, such as vesicoureteral reflux (VUR). Female mutation carriers may also have uterine or ovarian abnormalities. Renal aplasia falls at the most severe end of the spectrum of congenital anomalies of the kidney and urinary tract (CAKUT; see 610805) (summary by Brophy et al., 2017 and Sanna-Cherchi et al., 2017).