Arthritis Risk Alleles Validated Across Ethnicities
Genetic etiology of RA similar between those of European ancestry, African-Americans
WEDNESDAY, Dec. 22 (HealthDay News) -- The majority of validated risk alleles for patients with rheumatoid arthritis (RA) of European ancestry show similar odds ratios (ORs) in African-American patients with the condition, according to a report in the December issue of Arthritis & Rheumatism.
Laura B. Hughes, M.D., Ph.D., from the University of Alabama at Birmingham, and colleagues examined whether validated RA risk alleles for individuals of European ancestry were associated with RA risk in African-Americans. They used 27 candidate single-nucleotide polymorphisms (SNPs) genotyped in 556 African-American patients with RA and 791 healthy African-American controls and compared the ORs and confidence intervals (CIs) for each SNP to those of patients of European ancestry with RA. A genetic risk score (GRS) was calculated for each individual.
The researchers found that there was overlap of ORs and 95 percent CIs between the two populations in 24 of 27 candidate SNPs. Only one of the SNPs showed a statistically significant association with RA in African-Americans. The GRS analysis showed a small yet significant probability that, compared to the controls, African-American patients with RA were enriched for the risk alleles that have already been verified in European patients.
"The results of this study, however, demonstrated (via the GRS analysis) that, cumulatively, risk alleles for RA in Europeans also confer risk for RA in African-Americans. Therefore, we conclude that the two populations are best characterized as being genetically homogeneous with respect to validated risk alleles for RA," the authors write.
One author disclosed financial ties to Biogen Idec and Merck.