Unique association of hypochondroplasia with craniosynostosis and cleft palate in a Mexican family.

Hypochondroplasia (HCH) is a skeletal dysplasia caused by an abnormal function of the fibroblast growth factor receptor 3. Although believed to be relatively common, its prevalence and phenotype are not well established owing to its clinical, radiological, and genetic heterogeneity. Here we report on a molecularly proven HCH family with an affected father and two children. The siblings (male and female) with HCH also had craniosynostosis and cleft palate, respectively. The present report supports the conclusion that the full clinical spectrum of HCH is not completely delineated. It also suggests that secondary, as yet unknown, modifying factors can influence the final phenotype.