Four novel mutations of ADAR1 in Chinese patients with dyschromatosis symmetrica hereditaria.

BACKGROUND

Novel mutations in adenosine deaminase acting on RNA 1 gene (ADAR1) are responsible for dyschromatosis symmetrica hereditaria (DSH). DSH patients display a mixture of hyperpigmented and hypopigmented macules on the dorsal aspects of the extremities, and freckle-like macules on the face.

AIMS: To provide new evidence for further study of the etiopathogenisis of DSH.

METHODS

Genomic DNA was extracted and used as a template for the polymerase chain reaction (PCR) amplification of all 15 coding exons as well as intron-exon boundaries of ADAR1. The PCR products were sequenced directly.

RESULTS

We identified eight mutations of ADAR1 in four Chinese pedigrees and four individual patients, which were c.2722G>T, p.(Asp908Tyr), c.1657delA, p.(Ser553fs), c.2563_2564delCT, p.(Leu855fs), c.526T>G, p.(Leu176Val) as well as four previously reported mutations c. 3363_3364insT, p.(Lys1122fs), c. 2865_2866delGT, p.(Val955fs), c.1630C>T, p.(Arg544X), and c.2894C>T, p.(Pro965Leu). In silico analysis predicted that all the mutations reported were pathogenic.

LIMITATIONS: We did not study how ADAR1 played its role in DSH. So, the exact pathogenic mechanism of ADAR1 in DSH patients wasn't clarified in this study.

CONCLUSION

We found four novel ADAR1 mutations in this study. Our results enlarge the database on ADAR1 mutations associated with DSH.