Evidence for loss of heterozygosity in human psoriatic lesions

Psoriasis, a disease of human skin, is characterized by abnormal differenti ation and hyperproliferation of keratinocytes; it has a genetic background. Using 11 highly polymorphic microsatellite markers on eight chromosome arm s, we performed an allelotype analysis in 14 psoriatic plaques, in order to reveal any chromosome deletions involved in the development of the disease . We detected loss of heterozygosity (LOH) on at least one microsatellite m arker in nine of 14 (64%) cases, We also observed particular genetic loci a ltered with LOH, on chromosomes 3p, 7p/q and sp, Our results suggest that L OH is an important phenomenon in the development of psoriatic plaques, prov iding evidence for deletion of regulatory genes.