Mayer-Rokitansky-Kuster-Hauser syndrome (MRKH) is characterized by uterovaginal atresia in an otherwise phenotypically normal female with a normal 46,XX karyotype. Anomalies of the genital tract range from upper vaginal atresia to total mullerian agenesis with urinary tract abnormalities. It has an incidence of approximately 1 in 5,000 newborn girls (Cheroki et al., 2006). The abnormality of sexual development in MRKH syndrome is the same as that in the MURCS association (601076), in which cervicothoracic somite anomalies, unilateral renal agenesis, and conductive deafness are also seen. Mullerian aplasia and hyperandrogenism (158330) is caused by mutation in the WNT4 gene (603490). Familial cases of unilateral or bilateral renal agenesis in combination with mullerian anomalies have also been reported (see urogenital adysplasia, 191830).