A novel deletion mutation of the DSRAD gene in a Taiwanese patient with dyschromatosis symmetrica hereditaria

Conflicts of interest: None declared. Dyschromatosis symmetrica hereditaria (DSH; reticulate acropigmentation of Dohi,1 symmetric dyschromatosis of the extremities, leucopathia punctata et reticularis symmetrica,2 acropigmentatio symmetrica Dohi–Komaya;3 OMIM 127400) is a pigmentary genodermatosis characterized by onset in infancy or early childhood of a mixture of hyperpigmented and hypopigmented macules of various sizes on the dorsal aspects of the extremities, and freckle‐like macules on the face. This condition was first described by Toyama4 in a Japanese family and was coined DSH in 1929.5 DSH has been reported mainly in Japan and China but also in many other ethnic groups.6 DSH generally shows an autosomal dominant pattern of inheritance with high penetrance, but sporadic cases have been reported. Recently, two groups of researchers7, 8 reported pathogenic mutations in the gene of double‐stranded RNA‐specific adenosine deaminase (DSRAD), one of the RNA‐editing enzymes, among Japanese and Chinese patients with DSH. We report the identification of a Taiwanese boy with DSH and seizure, mental retardation and autistic disorder, in whom a novel deletion mutation (2645delG) in the DSRAD gene was demonstrated.