Objective To detect mutations in the ARAD1 gene in a pedigree with dyschromatosis symmetrica hereditaria (DSH).Methods Genomic DNA was extracted from the peripheral blood of 8 family members (including 5 patients with DSH and 3 unaffected members) in the pedigree with DSH,as well as 100 unrelated healthy controls.All the 15 exon sequences of the ADAR1 gene were amplified by polymerase chain reaction (PCR)followed by direct sequencing.Then,mutations were detected in comparison with the standard sequence of the ADAR1 gene in Genebank.Results A nonsense mutation C.1420C > T (p.Arg474X) was identified at position 1 420 in exon 2 of the ADAR1 gene in the 5 patients with DSH,but not in the 3 unaffected members or 100 unrelated healthy controls.Conclusion The nonsense mutation C.1420C > T in the ADAR1 gene is the causative mutation in the pedigree with DSH.