POLH and dyschromatosis symmetrica hereditaria: In this study, we performed whole-exome sequencing of an XP family, which had been suspected as having dyschromatosis symmetrica hereditaria (DSH), and a novel XP pathogenic homozygous nonsense mutation (c.353dupA, p. Y118_V119delinsX) was identified in the POLH gene (NM_006502).