Spectrum of phenotypic manifestations from a single point mutation of the p63 gene, including new cutaneous and immunologic findings.

Mutations in the p63 gene have been identified in five human disorders characterized by varying degrees of limb anomalies, ectodermal dysplasia, and facial clefts. We report a new point mutation in the p63 gene in a family in which the mother was initially diagnosed with Rapp-Hodgkin syndrome and her two offspring manifested ankyloblepharon, ectodermal defects, cleft lip and palate, syndrome. These three patients are the first to be reported with this particular mutation, which consists of a change from glycine to aspartic acid at position 506 on exon 14. The clinical spectrum observed in the three family members highlights the wide range of phenotypic variations that result from a single point mutation in the p63 gene. The mother lacks certain features classically associated with AEC, dermatitis of the scalp in particular. Severe erosive dermatitis of the scalp developed in both offspring, along with previously undescribed poikilodermatous skin changes and a deficiency of CD4 T lymphocytes. The new and varied phenotypic features noted in these patients emphasize the spectrum of disease caused by mutations in the p63 gene and raise the possibility of a role for it in maintaining immunocompetence.