Dyschromatosis symmetrica hereditaria (DSH) is an autosomal dominant pigmentary genodermatosis, characterized by a mixture of hyperpigmented and hypopigmented macules that are mainly present on the dorsal portions of the extremities. The DSH locus was mapped to chromosome 1q11-q12 and, subsequently, pathogenic mutations in the double-stranded RNA-specific adenosine deaminase (ADAR1) gene were identified. We performed a mutational analysis of the ADAR1 gene in a Chinese family that included three individuals affected with typical DSH phenotypes. Mutations within the entire coding region and the exon-intron boundaries of ADAR1 were detected and confirmed by polymerase chain reaction and direct sequencing, respectively. An insertion mutation within exon 12, c.3035_3036insC (p.P1012fsX1017), was identified in all family members affected by DSH, but not in the healthy members or 100 unrelated controls. This finding improves our understanding of the role of ADAR1 in DSH.