A novel missense mutation (Gln306His) in exon 7 of the ED1 gene causing anhidrotic ectodermal dysplasia with prominent milia-like facial sebaceous papules

Abstract

Sir, Anhidrotic ectodermal dysplasia (EDA; OMIM 305100) is an X‐linked recessive disorder that is clinically characterized by the triad of anodontia, hypotrichosis and anhidrosis. The affected organs are of ectodermal origin, but the nervous system is unaffected. The gene encodes a transmembrane protein of 391 amino acids (isoform II),1 which plays a critical role in morphogenesis of teeth, hair and sweat glands. Mutations in this gene were first reported in 1996.2 To date, 76 mutations have been reported (Human Gene Mutation Database, to 23 December 2002). These comprise 51 nucleotide substitutions, 15 microlesions and 10 gross deletions. Sebaceous papules on the face in EDA were described in the early literature,3–8 when gene mutations could not be specifically identified. We report a young man with prominent facial sebaceous papules with a novel mutation in the ED1 gene. Since birth, a 19‐year‐old Taiwanese man had had complete absence of teeth and recurrent fever without infection. He had had intolerance to heat since childhood, and usually avoided hot environments to prevent attacks of fever. His nails were all normal and no mental retardation or other anomaly was found. He had no pubic or axillary hair, and scanty hair on the scalp. Examination showed a characteristic facial appearance including a prominent forehead and supraorbital ridges (frontal bossing), a depressed nasal bridge (saddle nose) and protruding thick lips. In addition, many white milia‐like papules, discrete or aggregated in plaques, had been present on his forehead, cheeks and chin (Fig. 1a) since puberty. Skin biopsy from the palm revealed no sweat glands at all, and skin biopsy from a milia‐like papule revealed several sebaceous lobules surrounding vellus hair, which did not grow in a normal shape and direction (Fig. 1b). His only brother was free from similar symptoms or signs. His parents refused history taking and physical examination.