Evidence for two susceptibility loci on chromosomes 22q12 and 6p21-p22 in Chinese generalized vitiligo families.

Vitiligo is an acquired depigmentation disorder of the skin and hair caused by the selective destruction of melanocytes from the epidermis that gives rise to well-defined depigmented patches. Strong genetic predisposition has been well recognized. Previous reports have described five significant vitiligo susceptibility loci spread over five different chromosomes, 1p31 (AIS1), 7q (AIS2), 8p (AIS3), 4q13-q21 (AIS4), and 17p (SLEV1). In addition, our previous genome-wide scan of 106 Chinese vitiligo families presented suggestive linkages on five additional chromosome segments, 1p36, 6p21-p22, 6q24-q25, 14q12-q13, and 22q12. To clarify the significance of these suggestive loci, we have now extended this study to a total of 143 Chinese vitiligo families and increased the marker density. Two linkage signals on 6p21-p22 and 22q12 that were previously only suggestive now meet genome-wide criteria for significant linkage, establishing their importance as major vitiligo susceptibility loci. Linkage signals on 1p36 and 6q24-q25 did not improve our previous findings, but on 14q showed negative in the 143 family cohorts. The results presented here further demonstrate the genetic complexity of vitiligo pathogenesis and point to new chromosomal locations for further research to identify the specific genes involved in this process.