Seven novel mutations of ADAR in multi-ethnic pedigrees with dyschromatosis symmetrica hereditaria in China

Abstract

Background: Dyschromatosis symmetrica hereditaria (DSH;OMIM: #127400) is a rare autosomal dominant skin disease of hyperpigmented and hypopigmented macules on the dorsal aspects of the feet and hands. The adenosine deaminase RNA-Specific (ADAR;OMIM: *146920) gene was identified as causing DSH. Although more than 200 mutations are reported, no research has included the pedigrees of ethnic minorities in China. To investigate clinical features and genetic factors among multi-ethnic families, seven multi-ethnic pedigrees with DSH were collected for analysis of hereditary characteristics and ADAR mutations.

Methods: All 15 exons and exon-intron sequences of the ADAR gene were amplified and Sanger sequenced from 25 patients and 36 normal controls from seven multi-ethnic DSH families with 100 healthy normal controls. Seven mutations were analyzed by Polyphen 2, SIFT and Provean. All mutations in ADAR with DSH were reviewed and genetic and clinical features were summarized for analysis. The ADEAMc domain may be a hot spot of ADAR mutations among patients with DSH.

Results: Seven novel mutations were identified in seven multi-ethnic pedigrees: c.497delA(p.Arg105fs), c.3352C>T(p.Gln1058*) and c.3722delT(p.Ser1181fs) were found in three Uygur families with DSH; c.1330A>G(p.Val332Met) and c.2702A>T(p.His841Leu) were found in two Kazakh pedigrees and c.1176G>A(p.Lys326Glu) and c.2861G>A(p.Arg892His) in two Hui pedigrees. We summarized 203 different mutations of ADAR from people with DSH.

Conclusions: Seven novel mutations were identified in seven multi-ethnic families with DSH. Our study expands the genetic spectrum of ADAR mutations in DSH.

Keywords: China; adenosine deaminase acting on RNA; dyschromatosis symmetrica hereditaria; mutation.