To evaluate the role of the T cell receptor beta chain locus (TCRB) in genetic susceptibility to rheumatoid arthritis (RA).
Twenty-eight multiplex RA families were recruited from 3 rheumatology outpatient departments. All members were genotyped for a highly informative microsatellite (V beta 6.7), a V beta 12.2 SSCP marker, and a biallelic C beta restriction fragment length polymorphism. Data were analyzed by the SIBPAL program to assess identity-by-descent in affected sib-pairs.
Using the V beta 12.2 marker, there was suggestive evidence of increased sib-pair sharing (P = 0.005) in affected offspring (a P value of 0.001 is generally taken to establish linkage). Data for V beta 6.7 and C beta yielded significance levels of 0.06 and 0.19, respectively.
These data suggest that a gene in or linked to the TCRB complex may confer genetic susceptibility to RA in these families. Confirmation in a larger panel of families is required.