Agenesis of the sacrum and coccyx.
D002675:Child, Preschool; D003050:Coccyx / Q000002:abnormalities; D006801:Humans; D008297:Male; D009461:Neurologic Manifestations; D012445:Sacrococcygeal Region / Q000002:abnormalities*; D012447:Sacrum / Q000002:abnormalities