Evidence for a single genetic locus in Clouston's hidrotic ectodermal dysplasia.

Abstract

Sir, Clouston's hidrotic ectodermal dysplasia is a rare autosomal dominant ectodermal dysplasia first reported by Nicolle and Hallipré.1 A large French‐Canadian family was subsequently described by Clouston.2 The disease in this family has been linked to the chromosomal region 13q11–q12.1 by Kibar et al.3 Following the demonstration of linkage to 13q11–q12.1 in a number of other families4, 5 linkage analyses were performed on a large pedigree of Chinese–Malay descent with Clouston's hidrotic ectodermal dysplasia (HED).6 Fourteen affected members in three generations of the Chinese–Malay family were examined. The palmoplantar specific keratoderma was inherited as an autosomal dominant with complete penetrance but variable expressivity. A diffuse warty palmoplantar keratoderma developed over the entire sole and the hypothenar eminence of the hands. The skin changes extended to involve the periungual regions of the nails. The nail changes were variable and ranged from discoloured, thickened and dystrophic nails to hypoplasia with a classical cone‐shaped or triangular nail. The distal ends of the fingers were thickened and the digits appeared ‘clubbed’. The hair loss was variable and appeared progressive. Some developed a severe alopecia in infancy while in others it occurred later. The eyebrows, eyelashes, pubic and axillary hair were almost invariably involved and were either very sparse or lost completely. Sweating, teeth, breast development and oral mucosa all appeared normal.