Genome-Wide Association Study in Craniosynostosis Condition Using Innovative Systematic Bioinformatic Analysis Tools and Techniques: Future Prospective and Clinical Practice

A spectrum of TP63-related disorders with eight affected individuals in five unrelated families

TP63-related disdorders broadly involve varying combinations of ectodermal dysplasia (sparse hair, hypohydrosis, tooth abnormalities, nail dysplasia), cleft lip/palate, acromelic malformation, split-hand/foot malformation/syndactyly, ankyloblepharon filiforme adnatum, lacrimal duct obstruction, hypopigmentation, and hypoplastic breasts and/or nipples. TP63-related disorders are associated with heterozygous pathogenic variants in TP63 and include seven overlapping phenotypes; Ankyloblepharon-ectodermal defects-cleft lip/palate syndrome (AEC), Ectrodactyly-ectodermal dysplasia-cleft lip/palate syndrome 3 (EEC3), Limb-mammary syndrome (LMS), Acro-dermo-ungual-lacrimal-tooth syndrome (ADULT), Rapp-Hodgkin syndrome (RHS), Split-hand/foot malformation 4 (SHFM4), and Orofacial cleft 8. We report on five unrelated families with 8 affected individuals in which the probands presented with varying combinations of ectodermal dysplasia, cleft lip/palate, split-hand/foot malformation, lacrimal duct obstruction, and ankyloblepharon filiforme adnatum. The clinical diagnosis involved AEC syndrome (2 patients), EEC3 syndrome (2 patients), and a yet hitherto unclassified TP63-related disorder. Sanger sequence analysis of the TP63 gene was performed revealing five different variants among which four were novel and three were de novo. The identificated TP63 variants co-segregated with the other affected individuals in the families. The abnormalities of ectoderm derived structures including hair, nails, sweat glands, and teeth should alert the physician to the possibility of TP63-related disorders particularly in the presence of orofacial clefting.