Craniofrontonasal dysostosis: variable expression in a three-generation family.

A family with craniofrontonasal dysostosis (craniofrontonasal dysplasia) is described. There were three severely affected females, two of them daughters of apparently healthy parents. Examination of the male relatives revealed orbital hypertelorism and other minor anomalies in two of them, including the father of the two affected daughters. This family emphasizes the wide variation in the phenotype of craniofrontonasal dysostosis and suggests that male relatives with minor manifestations of the syndrome may be at high risk of having severely affected daughters. The expression of the gene may be modified by the sex.