Unknown syndrome: mental retardation with postaxial polydactyly, congenital absence of hair, severe seborrhoeic dermatitis, and Perthes' disease of the hip.

We report a six year old male with mental retardation, postaxial polydactyly and syndactyly, atrichia congenita totalis, severe seborrhoeic dermatitis, recurrent staphylococcal skin sepsis, and Perthes' disease of the hip. His birth may have resulted from an incestuous mating.