HLA-DQA1and DQB1Gene Polymorphisms In Populations Of South And North China

HLA class II genes include HLA-DP, HLA-DQ, HLA-DR, etc. HLA-DQA1and HLA-DQB1genes is highly polymorphic. The polymorphisms of HLA-DQA1and HLA-DQB1genes affect many autoimmune diseases, for example, HLA-DQ2gene (DQAl*0501-DQB1*0201) and DQ8gene (DQA1*0301-DQB1*0302) are related to type I diabetes, rheumatoid arthritis and celiac disease. In order to analyze the distribution characteristic of HLA-DQA1alleles, HLA-DQB1alleles and DQA1-DQB1haplotypes, the HLA-DQA1and DQB1gene polymorphisms in300individuals from different regions and nationalities of China were investigated. The distribution of the susceptibility genes of celiac disease (HLA-DQ2and DQ8genes) were also analyzed in this work.The study mainly focused on the extraction of DNA from the blood clot samples of300individuals, calculation of the HLA-DQA1and DQB1alleles frequencies and DQA1-DQB1haplotypes frequencies, analysis of the distribution characteristics of the HLA-DQA1and DQB1alleles, the haplotype DQA1*0501-DQB1*0201, the haplotype DQA1*0301-DQB1*0302/3and other DQA1-DQB1haplotypes. The methods, results and conclusion were shown as follows.1. DNA was extracted from the blood clot samples using one DNA extraction kit. The OD260and OD280value were measured by UV spectrophotometer to identify the purity and the concentration of the DNA. It was shown that the purity of the DNA (OD260/OD280) was between1.6to1.9, and the concentration was within0.05-0.5μg/μL. The purity and the concentration of the DNA were suitable for the further work of PCR.2. The DNA extracted from blood clot were amplified with PCR-SSP method, and the amplification products were identified by agarose gel electrophoresis. The number of the HLA-DQA1and DQB1alleles in the300individuals was counted by direct calculation method, followed by calculating frequency of each allele. Arlequin, one human genetic data analysis software, was used to calculate the DQA1-DQB1haplotype frequency. It was shown that the frequencies of the alleles DQA1*0302, DQA1*0501and DQA1*0102were maximum in the HLA-DQA1alleles of Chinese people, and the frequency of the allele DQB1*0301was maximum in the HLA-DQB1alleles of Chinese people. The frequencies of the DQA1*0501-DQB1*0301, DQA1*0102-DQB1*0602, DQA1*0102-DQB1*0502, DQA1*0101/4-DQB1*0501and DQA1*0302-DQB1*0302/3were relatively high.3. SPSS, one statistical software, was used to statistically analyze haplotypes frequencies and alleles frequencies of the HLA-DQA1and DQB1in the following groups:the Northern population and the Southern population; Male and Female; Han and Minorities; Northern Han and Northern Minorities; Southern Han and Southern Minorities; Northern Han and Southern Han; Northern Minorities and Southern Minorities. It was shown that, DQA1*0102and DQB1*0502were more common in Southerners, while DQA1*0201was more common in northerners; the distribution of DQB1*0502in the Northern Han and Southern Han was significantly different, and the individuals who carry this gene were mostly Southern Han; The distributions of DQA1*0102and DQB1*0502in the population of Northern Minorities and Southern Minorities also was significantly different, and the two alleles were more common in the Southern Minorities; The distributions of the HLA-DQA1and DQB1alleles in the three groups-Han and Minorities, the North Han and Northern Minorities, Southern Han and Southern Minorities-were slight different, as only DQA1*0401was more common in Southern Minorities; DQB1*0502was more common in female.4. Arlequin, one human genetic data analysis software, was used to estimate and compare the haplotypes frequencies of the DQA1*0501-DQB1*0201and DQA1*0301-DQB1*0302/3in the Northern population and the Southern population, Han and Minorities, Male and Female.It was shown that, the haplotype frequency of the DQA1*0501-DQB1*0201in Southern population was higher than that in the Northern population, while the frequencies of the DQA1*0301-DQB1*0302/3in the two groups were similar. The frequencies of the two haplotypes in Han and Minorities were slight different, while that in Female were higher than that in Male.