Vitiligo-Associated Autoimmune Disease Gene Identified
Linkage study implicates innate immune system in autoimmune/autoinflammatory disease
WEDNESDAY, March 21 (HealthDay News) -- A mediator of the innate immune system may play a key role in the development of vitiligo and several epidemiologically related autoimmune and autoinflammatory diseases, according to a report in the March 22 issue of the New England Journal of Medicine.
Richard Spritz, M.D., of the University of Colorado at Denver and Health Sciences Center in Aurora, Colo., and colleagues collected DNA from 656 individuals from 114 families in the United States and United Kingdom. Each family had at least two members with vitiligo and at least one with an additional, associated autoimmune or autoinflammatory disease. The team genotyped single-nucleotide polymorphisms (SNPs) on the short arm of chromosome 17 to identify genes linked to vitiligo-associated multiple autoimmune disease.
The team identified a region with a maximal multipoint lod score of 4.59 and centered at 4.3 cM, that likely contained a gene associated with the disease. SNP genotyping and DNA sequencing identified one candidate gene, NALP1 (NACHT leucine-rich-repeat protein 1, a gene implicated in the innate immune response). Variants of the gene were associated with vitiligo alone, autoimmune and autoinflammatory disease, or both. At least two independent variants, one within the gene itself and a second in the promoter, contributed to disease risk.
The authors note, however, that "the SNPs that we have implicated may not be the causal variants; identification of such variants will require the demonstration of specific effects on NALP1 transcription, mRNA, or protein function."