Restriction fragment length polymorphism of the T cell receptor beta-chain gene in Chinese patients with thyrotoxic hypokaleamic periodic paralysis and Graves' disease.

Restriction fragment length polymorphism (RFLP) of the T cell receptor beta-chain gene was studied in two groups of Chinese thyrotoxic patients, those with thyrotoxic hypokaleamic periodic paralysis (THPP) and those with Graves' Disease (GD). DNA digested with restriction enzymes Bgl II, Bam HI, Eco RI, Pvu II and Taq I were hybridized to a 770 bp TcR beta cDNA probe containing the joining (J) and constant (C) region segments. The TcR beta/Bgl II polymorphism of 9.2 kb and 10 kb fragments were observed in THPP, GD and normal controls. The genotype frequencies of this polymorphism, however, did not differ between patients (THPP or GD) and controls. These results, therefore, do not support the presence of an association between the TCR beta/Bgl II RFLP and THPP nor with GD susceptibility. Finally, restriction analysis of DNA from our patients and normal controls using enzymes Bam HI, Eco RI, Pvu II and Taq I with the T cell receptor beta-chain gene did not show polymorphisms, and were therefore not informative.