Screening of EDA1 gene in X-linked anhidrotic ectodermal dysplasia using DHPLC:: Identification of 14 novel mutations in Italian patients

Mutations within EDA1 gene, which encodes for the ectodysplasin, cause X-linked anhidrotic ectodermal dysplasia. In this study, 23 Italian patients with anhidrotic ectodermal dysplasia were analyzed for mutations in EDA1 gene. We set up a rapid protocol through denaturing high-performance liquid chromatography, followed by sequencing, that allowed the characterization of 18 mutations, 14 novel and 4 recurrent: 8 missense mutations (p.L51Q, p.H54R, p.R156H twice, p.C332F, p.D316H, p.T378M, and p.A349T), 3 in-frame deletions (p.G82_P84del, p.A179_P191del, and p.L354del), 1 gross deletion (p.G168_G265del, identified through direct sequencing and PCR), 4 altered splicing (c.949-13T> C, c. 741 + 1G/T, c. 793 + 4A> T, and c. 924 + 1G/T), 1 nonsense (p.Y3X), and 1 synonymous mutation (c.741G> A). Moreover, structural analysis of three missense mutations shows that alteration of the electrostatic surface of the protein (p.D316N), the break of intermonomer interactions (p.A349T) and destabilization of the single monomer structure (p.T378M), may irreversibly invalidate the EDAA1 binding properties. Our data confirm and extend the large spectrum of EDA1 mutations and provide a rapid and efficient molecular protocol for testing EDA1 mutations in EDA patients.