最大似然法和方根法计算HLA三座位单体型频率的比较  

Comparison of EM and square root algorithms applied to estimate HLA-A-B-DR haplotype frequency

作　　者：王珏[1] 罗玫[1] 邹海[2] 甘静[2] 李星洁[2] 陈强[1,2] 郑忠伟[1] 

机构地区：[1]中国医学科学院北京协和医学院输血研究所,四川成都610081 [2]四川省脐带血造血干细胞库

出　　处：《中国输血杂志》2009年第7期546-549,共4页Chinese Journal of Blood Transfusion

摘　　要：目的研究在不同样本量条件下,方根法和最大似然法计算HLA-A-B-DR三座位单体型的准确性。方法选择100例有家系资料的个体,以方根法和最大似然法分别计算其单体型频率,并与家系分析结果相比较。从四川骨髓库中选择8 933例无关个体,比较2种方法计算得到的单体型频率。结果在标本量分别为100例和8933例时,2种方法得到的最常见单体型分布差异无统计学意义。方根法计算结果中有大量单体型频率为负值,频率为正的单体型累计频率>1。结论总体来说,最大似然法比方根法更加准确,但2种算法得到的最常见单体型频率差异无统计学意义。Objective To investigate the accuracy of haplotype frequency （HF） estimate algorithms applied to estimate HLA-A-B-DR HFs. Methods The haplotypes of 100 individuals with pedigree information were deduced following the rules of Medelian segregation. HFs of these 100 individuals were estimated by EM and square root algorithms, which were compared with the pedigree results. The HFs of 8 933 unralted indviduals from Sichuan Cord Blood Bank, determined by two algorithms were also compared. Results The frequencies of most common haplotypes in the 100 and 8 933 individuals determined by two algorithms were similar（ P 〉 0. 05 ）. Most of the HFs values calculated by square root algorithm were negative, and the sum of the postive values were greater than 1. Conclusion EM is superior than square root algorithm in HF estimation. However, the results of both algorithm for the highest HFs are comparable.

关 键 词：最大似然法 方根法 HLA 单体型 

分 类 号：R457.11[医药卫生—治疗学]