Palmoplantar keratoderma and erythrokeratodermas

Gene: GJB6

Green List (high evidence)

Comment on list classification: Updated rating from Red to Green after discussion with Helen Brittain: Clouston syndrome phenotype includes PPK, and 3 unrelated cases of GJB6 variants supporting causation of Clouston syndrome.

Created: 3 Apr 2017, 11:18 a.m.

PMID:27137747 (Yang et al., 2016) identify a heterozygous missense mutation c.263C>T (p.A88V) in GJB6 in a Chinese family with Clouston syndrome. Hyperkeratosis of the palms and soles was more severe in elderly patients than in younger ones.

Created: 3 Apr 2017, 11:15 a.m.

Agarwal, 2016 (PMID:27643550) report a GJB6 mutation in an Indian man with Clouston syndrome.The patient had complaints of excessively thickened skin of the palms and soles. On examination, the patient was found to have severe hyperkeratosis of the palms and soles which led to clawing of the hands.

Created: 23 Mar 2017, 10:51 a.m.

Smith et al, 2002 (PMID:11874494) report a novel mutation V37E in GJB6 in a spontaneous case of Clouston syndrome.

Created: 23 Mar 2017, 10:49 a.m.

Ectodermal dysplasia (ECTD2; OMIM:129500), also known as Clouston syndrome is an autosomal dominant skin disorder caused by mutations in GJB6, and characterized by palmoplantar hyperkeratosis, hair defects (from partial to total alopecia), nail hypoplasia, and nail deformities.

Created: 22 Feb 2017, 5:45 p.m.