T cell receptor alpha-chain polymorphic allele frequencies in Caucasians and Polynesians.

Restriction length polymorphisms in the variable and constant regions of the T cell receptor alpha-chain were examined in 42 Caucasians, 29 Maoris and 27 Pacific Islanders. Southern blots of Taq I digested DNA were hybridized with the T cell receptor alpha-chain probe pY14. Our results confirm that a 1.4 kb T cell receptor alpha chain-Taq 1 band is allelic to a 0.5 kb band. A significant difference in the frequency of the 1.4 and 0.5 kb alleles of the variable region of the alpha-chain was detected in Caucasians when compared with Maoris or Pacific Islanders (P < 0.0001). No differences in the frequency of the 2.0 and 7.0 kb alleles of the constant region gene were detected between any of the racial groups. These data may be relevant to ethnic differences in susceptibility to immune disorders.