Variable expressivity of Crouzon's syndrome within a family.

Three individuals in two generations affected with Crouzon's syndrome are reported. The proband, a 10-year-old boy, had been diagnosed until the age of 4. His 3-year-old sister had not been diagnosed previously and his mother was unaware of having the syndrome and had never received any genetic counseling. The individuals are reported with emphasis on clinical and roentgencephalometric variation. The ultimate goal in teratolgoy is prevention. Currently one of the most important factors related to prevention is genetic counseling in conditions with well-documented modes of inheritance. The present report describes how the variable expressivity of Crouzon's syndrome within a family had caused diagnostic problems and consequently had delayed genetic counseling.