Refining the position of loci on chromosomes 7 and 9 previously linked with generalized vitiligo or vitiligo-associated autoimmune diseases presenting in families has been performed by high-density single-nucleotide polymorphism (SNP) genotyping. Investigation of the genetic interaction among these loci (and with a previously identified susceptibility gene, NLRP1, on chromosome 17) as risk factors for vitiligo demonstrates the complex nature of this disease.