Pedigree of the family. The proband's mother (III4), who is an obligate carrier, had a normal renal US scan and normal thoracic radiographs. She had three marriages (III3, 5, 6) and four gestations, including IV2 (index case) and IV3, 4 (two boys aged 15 and 5, respectively). In IV3, right renal agenesis was diagnosed. We have not observed associated genital anomalies. IV4 was prenatally diagnosed at 20 weeks with a dysplastic right kidney. He has associated genital anomalies (absent right testis). Subject IV5 has a normal phenotype. The mother and sister of III4 have normal US scans and radiographs. III4 described lung hypoplasia diagnosed at autopsy in her father (II2) and grandfather (I1). Grey squares indicate lung hypoplasia reported by subject III4 but not documented with a clinical history.