A family with three recessive traits and homozygosity for a long 9qh+ chromosome segment.

We report a family in which a mentally retarded, proportionately dwarfed girl had a child from a presumably incestuous mating that had the Ellis van-Creveld syndrome, presumed autosomal recessive hydrocephalus (Dandy-Walker type), and homozygosity for an extremely long 9qh+ chromosomal marker. The mentally retarded mother had normal birth weight, unusual facial appearance, and virtual absence of secondary sexual hair; she developed severe hypoglycemia during pregnancy. Her parents were first cousins, and she may have a previously unreported autosomal recessive syndrome.