The influence of age at onset and gender on the HLA-DQA1, DQB1 associationin Chinese children with insulin dependent diabetes mellitus

Certain alleles of human leukocyte antigen (HLA)-DR and -DQ genes have been strongly associated with susceptibility and resistance to insulin- depende nt diabetes mellitus (IDDM). To further clarify the association of HLA DQ a lleles with IDDM and the influence of age at onset and gender on the associ ation with IDDM, me investigated the association of HLA-DQA1, -DQB1 in 54 c hildhood onset Chinese (21 male) IDDM patients and 65 normal controls by us ing polymerase chain reaction-sequence specific primer (PCR-SSP). The mean age plus or minus SD at onset of IDDM I patients was 8.37 +/- 3.54 year old . Our results revealed that the frequencies of DQA1 *0301, *0302, DQB1 *020 1, and *0302 in IDDM patients were significantly higher than that in the co ntrol group (p < 0.025, < 0.005, < 0.001, and < 0.001, respectively). The f requency of DQA1 *0301, *0302, DQB1 *0201, and *0302 were susceptible allel es to IDDM with relative risks of 2.0, 3.5, 5.0 and 4.3, respectively. The protective alleles to IDDM were DQA1 *0101, *0103, DQB1 *0301, *0503, and * 0602. We divided IDDM patients into three groups according to age at onset (1-5, 6-10, and 11-15 years old). The frequency of DQA1 *0302 decreased as age increased, and the frequency of DQA1 *0501 increased as age increased. Our results also showed that: male IDDM patients had higher frequencies of DQA1 *0501, DQB1 *0201 than female IDDM patients (p < 0.025 and < 0.025, re spectively), while female IDDM patients had higher frequencies of DQB1 *050 2 than male IDDM patients (p < 0.05). In our study significant susceptibili ty haplotypes to IDDM mere DQA1 *0301-DQB1 *0302, DQA1 *0501-DQB1 :*0201, D QA1 *0301-DQB1 *0201, and DQA1 *0302-DQB1 *0201. Human Immunology 60, 1131- 1137 (1999). (C) American Society for Histocompatibility and Immunogenetics , 1999 Published by Elsevier Science Inc.