Objective: To investigate association between asthma and HLA-DQ genes in Chinese asthma family.
Methods: HLA genotyping was done for HLA-DQ using polymerase chain reaction-sequence specific primers (PCR-SSP) in 98 members of 32 Chinese asthma families and 67 normal controls.
Results: The allele frequencies of DQA1 * 0101 and DQA1 * 0601 in asthmatics (40.0% and 45.0% respectively) were significantly higher than those in normal controls (16.4% and 13.4% respectively; chi(2) = 6.1860, P < 0.05, RR = 3.39 and chi(2) = 11.609 0, P < 0.01, RR = 5.27 respectively). The allele frequencies of DQB1 * 0303 and DQB1 * 0601 in asthmatics (55.0% and 47.5% respectively) were also significantly higher than those in normal controls (13.7% and 13.7% respectively; chi(2) = 15.740 0, P < 0.01, RR = 7.68 and chi(2) = 10.930 0, P < 0.01, RR = 5.69 respectively). The allele frequency of DQ * 0201 (39.4%) was significantly higher in members with positive specific IgE response to dermatophagoides than that in non-atopy members (12.0%) in asthma family (t = 2.382 5, P < 0.05).
Conclusion: HLA-DQA1* 0101, DQA1 * 0601 and HLA-DQB1 * 0303, DQB1 * 0601 may be the susceptible alleles of asthma. HLA-DQB1 * 0201 allele may limit the specific IgE response to dermatophagoides.