Genetic association of NALP1 with generalized vitiligo in Jordanian Arabs

Generalized vitiligo is an autoimmune disorder characterized by patchy loss of pigmentation due to autoimmune destruction of melanocytes in the involved areas. Vitiligo is a polygenic, multifactorial disorder involving multiple genes and unknown environmental triggers. Recently, genetic variation in NALP1 (also called NLRP1), encoding a key regulator of the innate immune response, has been associated with generalized vitiligo in Caucasians of northern European origin. Here, we have investigated whether NALP1 is also associated with generalized vitiligo in Jordanian Arab patients. We genotyped 8 NALP1 single-nucleotide polymorphisms (SNPs) in 26 generalized vitiligo patients and 61 matched controls unaffected by vitiligo or any other autoimmune disorder. We found that two SNPs in the NALP1 extended promoter region, rs1008588 and rs2670660 were significantly associated with generalized vitiligo in our cohort of Arab vitiligo patients, and several other SNPs in the NALP1 region were at the margin of significant association. These results indicate that NALP1 is associated with susceptibility to generalized vitiligo in Arabs, as in Caucasians. Whether the casual variants are the same of not is yet to be identified by functional analysis.