Ectodermal Dysplasia-Syndactyly Syndrome 2

For a general phenotypic description and a discussion of genetic heterogeneity of ectodermal dysplasia-syndactyly syndrome, see EDSS1 (613573).

Clinical Features

Tariq et al. (2009) described a novel ectodermal dysplasia-syndactyly syndrome, which they called ectodermal dysplasia-cutaneous syndactyly (EDCS), in 4 sibs of first-cousin Pakistani parents. Clinical features included large prominent ear pinnae, tooth enamel hypoplasia, hypoplastic nails, bilateral partial cutaneous syndactyly, hypotrichosis, palmoplantar keratoderma, and hyperhidrosis. Tariq et al. (2009) suggested the disorder was distinct from other reported ectodermal dysplasia-syndactyly syndromes by such features as thin body hairs, hypoplastic flat and yellowish fingernails and toenails, plantar keratoderma, hyperhidrosis, cardiomegaly, follicular hyperkeratosis, hard scaly skin with mild epidermolytic hyperkeratosis, pointed nose, thin upper lips, and large prominent ear pinnae.

Inheritance

Affected sibs of first-cousin parents in the Pakistani family with EDSS2 described by Tariq et al. (2009) suggested autosomal recessive inheritance.

Mapping

By genetic linkage analysis in the Pakistani family with EDSS2, Tariq et al. (2009) mapped the disorder to chromosome 7p21.1-p14.3 flanked by markers D7S488 and D7S817. A maximum 2-point lod score of 2.94 was obtained at marker D7S2496, whereas a maximum multipoint lod score of 3.07 was obtained with several markers along the disease interval. This interval contained more than 50 known genes. Sequence analysis of 27 candidate genes in the interval did not reveal any functional sequence variant.