Five novel mutations of RNA-specific adenosine deaminase gene with dyschromatosis symmetrica hereditaria.

Dyschromatosis symmetrica hereditaria (OMIM127400) is a rare autosomal dominant pigmentary genodermatosis caused by mutations in the RNA-specific adenosine deaminase (ADAR) gene. This study investigated 5 families and 3 sporadic patients with dyschromatosis symmetrica hereditaria in the Chinese Han population from Anhui province, China. By direct sequencing, 5 novel ADAR gene mutations (c.982C>T, c.1491insA, c.2568_2571delTAAC, c.2969C>G and c.3040G>T) and 3 mutations described previously (c.3203-2A>G, c.3247C>T and c.3286C>T) were identified, all of which were heterozygous. We reviewed a total of 48 mutations in the ADAR gene in patients with dyschromatosis symmetrica hereditaria by previous reports and speculated that the mutation hotspots on the ADAR gene might be located in exons 9-15. The tRNA-specific and double-stranded RNA adenosine deaminase domain is essential for the deaminase activity of the ADAR encoded protein.