|Disease group||Ectodermal Dysplasia|
|DISEASE NAME||CLOUSTON SYNDROME|
|Synonymous||Hidrotic ectodermal dysplasia|
|Gene (s)||GJB6 (604418)|
Hidrotic ectodermal dysplasia is a rare autosomal dominant ectodermal dysplasia disorder first described by Clouston in 1929. Characteristic clinical features include nail dystrophy, sparse hair (total alopecia is common), skin hyperpigmentation (especially over joints) and occasionally palmar hyperkeratosis.
In contrast to X-linked HED (hypohidrotic ectodermal dysplasia), patients have normal sweating and no teeth abnormalities. However, other ectodermal structures may be affected: nails are hypoplastic or dystrophic and hair (scalp and body) is hypochromic, fine and sparse. Total alopecia is common.
Lamartine et al. (2000) identified mutations in the GJB6 gene (locus 13q12) which encodes connexin-30 as the molecular basis of Clouston syndrome. Connexins are involved in the formation of gap junctions which are intercellular channels connecting the cytoplasm of adjacent cells.
In more severe cases, the diagnosis is usually made soon after birth. However, in milder cases,children may only be diagnosed clinically when nails or hair fail to develop normally.
The management of Clouston syndrome requires management of palmar hyperkeratosis with topical treatment that mayinclude emollients, keratolytics (eg 6% salicylic acid in 70% propylene glycol), topical retinoids, topical vitamin D ointment (calcipotriol) and systemic retinoids.