Variable expression of campomelic dysplasia in a father and his 46, XY daughter

Campomelic dysplasia (CD, MIM 114290) is characterised by widespread osseous abnormalities including bowing of the long bones, dysplasia of the cartilage of the tracheobronchial tree, and neurological abnormalities leading to high perinatal lethality. A majority of karyotypic males present as phenotypic females. The disorder has only recently been categorised as a dominantly transmitted entity after demonstration of heterozygous mutations in the SOX9 gene on chromosome 17q24.3 or translocations associated with breakpoints upstream of this gene. Despite this mode of transmission, only two well-documented instances of parent-child transmission of the disorder have been described. We report a man of normal intelligence with mild phenotypic and radiological appearances of CD. His first-born child, a phenotypic female with a 46,XY karyotype, presented with significantly more severe skeletal and neurological involvement. Parents of individuals with CD should be examined for minimal manifestations of the disorder, which may represent phenotypic variability in the syndrome or somatic mosaicism.