Abstract

Craniofacial dysostosis, the Crouzon syndrome, occurs sporadically and in families; the clearly heritable form up to now has been autosomal dominant. We ascertained two similarly affected sibs, a brother and a sister, in a sibship of nine. Neither the Negro parents nor any ancestors nor collateral relatives were similarly affected. The parents were not consanguineous. After excluding other genetic and environmental explanations, we concluded that the reasonably typical findings of the disorder in the two sibs were probably genetically determined by a single, autosomal recessive gene.