Identification of the disease gene of dyschromatosis symmetrica hereditaria.

对称遗传性色素沉着症（DSH）是一种常染色体显性色素遗传病，由富山于1910年首次报道。它的特点是手背和脚背上出现各种大小的色素沉着和色素沉着的斑点。DSH的病因、发病机制、发病基因及其染色体定位尚未明确。因此，本项目对日本3个DSH家族（共83例患者）的DSH基因与各染色体上的微卫星标记进行连锁分析，以最终鉴定DSH基因。我们获得了3个LOD值大于5的微卫星标记，然后通过单核苷酸多态性（SNP）分析将候选基因的定位范围缩小到约3 Mb。我们现在试图找到在3Mb染色体区域识别的几个有希望的基因中的任何突变。

Dyschromatosis symmetrica hereditaria (DSH) is an autosomal dominant pigmentary disorder, first reported by Toyama in 1910. It is characterized by a mixture of hypopigmented and hyperpigmented macules of various sizes on the backs of the hands and feet. The cause and the pathogenesis as well as the disease gene of DSH and its chromosomal localization have not yet been clarified. Thus we made the project performing linkage analysis between the DSH gene and microsatellite markers on each chromosome in three Japanese DSH families (83 patients in total) in order to finally identify the DSH gene.We obtained three microsatellite markers showing high log ratio of odds (LOD) score more than 5 and then narrowed the location of the candidate gene to about 3 Mb after the single nucleotide polymorphism (SNP) analysis. We now try to find any mutation (s) in several hopeful genes recognized in the 3Mb chromosomal region.