T-cell antigen receptor gamma chain polymorphisms in type 1 diabetes.

ABSTRACT

The T-cell antigen receptor gamma chain, in conjunction with the delta chain, forms a functional receptor on a small percentage of circulating T-cells. Using restriction enzymes Msp 1 and Stu 1, and a human gamma chain cDNA probe, pT gamma 1, frequent restriction fragment length polymorphisms (RFLPs; 8 kb Msp 1 band; 7.6, 5.0, and 4.3/4.0 kb Stu 1 bands) were detected using DNA from healthy controls. These RFLPs allowed determination of parental alleles at the gamma chain locus, and follow up of their inheritance within families. Since Type 1 diabetes is an organ-specific autoimmune disease thought to be mediated by T-cells, the association of gamma chain polymorphisms with Type 1 diabetes was studied in a population study. No significant association was found with any of the polymorphic bands. The segregation of the gamma chain alleles among diabetic sibs in 6 multiplex families with Type 1 diabetes was also studied but linkage with diabetes could not be demonstrated.