T-CELL RECEPTOR POLYMORPHISMS IN TLINGIT INDIANS WITH RHEUMATOID-ARTHRITIS

Rheumatoid arthritis (RA) develops as a result of the interaction of b oth genetic and environmental factors. Among the genes in humans that have been suggested as candidate susceptibility genes in RA are those encoding the T cell receptor for antigen (TCR). A high prevalence and early age of onset of RA has previously been reported in Alaskan Tling it Indians. In this study, the frequency of seven different restrictio n fragment length polymorphisms (RFLPs) in the TCR alpha and beta gene complexes were measured in a population of Alaskan Tlingit Indians. N o statistically significant differences were noted when the frequencie s of these RFLPs were compared between Tlingits with RA and healthy co ntrols (p > 0.05). These results do not support the hypothesis of an R A-susceptibility allele in the vicinity of these TCR alpha or beta gen es. Since TCR RFLPs have not been extensively studied in native Americ an populations, TCR polymorphism frequencies in the Tlingits were also compared to the frequencies observed in a second control group of hea lthy Caucasians. Statistically significant differences were observed i n these comparisons implying a different distribution of individuals i n these populations with different TCR repertoires.