[HLA-DQA1 genes involved in genetic susceptibility to rheumatic fever and rheumatic heart disease in southern Hans].

The incidence of rheumatic fever (RF) or rheumatic heart disease (RHD) is high in southern China. We studied the genetic susceptibility of HLA-DQA1 alleles to RF or RHD with emphasis on the mechanisms 106 unrelated healthy individuals and 54 patients with RF or RHD of Chinese Han nationality in Guangdong were included. DNA extraction from various biological material using phenol/chloroform method and HLA-DQA1 genotyping by PCR-PAGE and then with silver dyeing was used to show the electrophoretic patterns. A total 6 alleles of HLA-DQA1 were found. Increased allele frequencies of DQA1*0101 (31.48%, RR = 2.89, P < 0.005, EF = 0.206) and decreased allele frequencies of DQA1*0102 (1.85%, RR = 0.106, P < 0.005, PF = 0.134) were observed. Two increased genotyping of HLA-DQA1 (DQA1*0101/0301, chi 2 = 8.84, P < 0.005 and DQA1*0101/0401, chi 2 = 6.23, P < 0.0025) and decreased genotyping of DQA1*0102/0301 (chi 2 = 11.98, P < 0.005) were also observed. These findings suggested that DQA1*0101 contribute to genetic susceptibility for RF or RHD in Guangdong hans while DQA1*0102 to its genetic resistance. Digesting the genotyping of HLA-DQA1 may provide scientific basis for finding susceptible individuals to RF or RHD. Using PCR-PAGE and silver dyeing technique, a new genotyping method for HLA-DQA1, which is simple sensitive and precise, was established and applied.