Molecular basis of EEC (ectrodactyly, ectodermal dysplasia, clefting) syndrome: five new mutations in the DNA-binding domain of the TP63 gene and genotype-phenotype correlation

P>EEC (ectrodactyly, ectodermal dysplasia, clefting; OMIM 604292) syndrome is an autosomal dominant developmental disorder. Characteristic clinical features comprise abnormalities in several ectodermal structures including skin, hair, teeth, nails and sweat glands as well as orofacial clefting and limb defects. Pathogenic mutations in the TP63 transcription factor have been identified as the molecular basis of EEC syndrome and to date 34 mutations have been reported. The majority of mutations involve heterozygous missense mutations in the DNA-binding domain of TP63, a region critical for direct interactions with DNA target sequences. In this report, we present an overview of EEC syndrome, discuss the role of TP63 in embryonic development and skin homeostasis, and report five new TP63 gene mutations. We highlight the significant intra- and interfamilial phenotypic variability in affected individuals and outline the emerging paradigm for genotype-phenotype correlation in this inherited ectodermal dysplasia syndrome.