HLA-A,B,DRB1单体型频率计算及其在骨髓库中的应用

目的从群体资料计算HLAA,B,DRB1三座位单体型频率,并用于骨髓库寻找HLA匹配供者。方法根据HLA表型群体资料,使用最大数学预期值算法(ExpectationMaximization,EM)计算HLA三座位单体型频率。通过实例运算介绍HLA表型频率以及发现HLA匹配无关供者的概率。结果①使用DNA基因分型技术鉴定12193例无关汉族健康个体HLA表型,计算求得HLAA,B,DRB1单体型频率。②预期概率与观察结果吻合,并用于评估骨髓库的最适大小。结论使用EM算法估计大样本汉族群体HLAA,B,DRB1三座位单体型频率,结果可靠,可用于评估骨髓库的最适大小和组份。

Estimation of HLA-A, B, DRB1 haplotype frequencies and its application

Objective To estimate the HLA-A, B, DRB1 haplotype frequencies and use the data in searching for HLA matched unrelated donors for hematopoietic stem cell transplantation.Methods Expectation-maximization(EM) algorithm was adopted to estimate HLA three-locus haplotype frequencies on the basis of HLA phenotype data.Results HLA-A, B, DRB1 haplotype frequencies were estimated from a pool of 12193 random health individuals typed using DNA-based HLA typing technique in a Han population. The formulas for calculating phenotype frequencies and the probabilities of finding HLA matched donors were provided. Data of searching for HLA matching donors indicated that the expected probabilities fit the observed data.Conclusion Reliable HLA-A, B and DR haplotype frequencies were estimated in a Han population using EM algorithm. The EM algorithm is found to perform best for large samples.Three-locus haplotype frequency data could be used to evaluate optimal pool size and composition in bone marrow donor registry database.