Objective: Graves' disease has been documented to be associated with different HLA genes in Caucasians and Chinese adults. The incidence of childhood Graves' disease has been reported to be high in Hong Kong Chinese. The aims of this study were to examine the HLA-DQA1 and DQB1 associations with Graves' disease in Chinese children.
Patients and design: Sixty-seven Chinese children with Graves' disease (59 girls and 8 boys) and 51 racially matched healthy controls were recruited for the study. Genomic DNA was extracted from venous blood samples. HLA-DQ typings were determined by sequence-specific oligonucleotide probing of the respective enzymatically amplified gene. Frequencies of HLA-DQ alleles at each locus were compared between patients and controls using the chi 2-test.
Results: The frequency of HLA-DQB1.0303 was increased in the combined male and female patient group [53.7%; relative risk (RR) = 4.22; Pc = 0.005] and female patients (50.8%; RR = 3.76; Pc = 0.018) compared with that in the entire control group (21.2%). HLA-DQB1*201 was protective for Graves' disease (10.4%; RR = 0.20; Pc = 0.006). In contrast to studies in Caucasians, DQA1*0501 was not associated with susceptibility for Graves' disease in Chinese children.
Conclusions: This study confirms that DQB1*0303 is a race-specific susceptible allele for Graves' disease in Chinese. Both susceptible and protective HLA-DQ alleles for Graves' disease in Chinese children are different from those in Caucasians.