Six novel mutations of the ADAR1 gene in Chinese patients with dyschromatosis symmetrica hereditaria

Abstract

Dyschromatosis symmetrica hereditaria (DSH) is a rare autosomal dominantly inherited dermatosis and characterized by a mixture of hyperpigmented and hypopigmented macules on the back of hands and feet. The DSH locus was mapped to chromosome 1q21 and subsequently pathogenic mutations were identified in the adenosine deaminase acting on RNA1 (ADAR1) gene in 2003. In this study, we performed a mutation analysis of the ADAR1 gene in eight Chinese families and one sporadic patient with typical DSH. PCR and direct sequencing of the ADAR1 gene were performed to identify and confirm the mutations in the eight families and the sporadic patient. Six novel and one known mutations were identified, including four missense mutations (p.K1105N, p.G1047R, p.F1099L, p.G1068R), two frameshift mutations (p.Q779fs-792x, p.P441fs-463x) and one nonsense mutation (p.R1096x). Six novel mutations were found in five unrelated families and one sporadic case, which have further improved our understanding on the role of ADAR1 in DSH. Interestingly, we failed to detect any mutations of ADAR1 in two families.