突变情形下亲权指数计算的新方法

目的介绍一种常染色体共显性遗传标记突变时的亲权指数（paternity index，PI）计算法。方法假定突变的等位基因在传给孩子之前以一突变概率发生突变．然后发生分离以1／2的机会传给孩子。而随机男子提供某一等位基因给孩子的概率为等位基因频率。一个案例中考虑仅有一次突变，通过比较亲代和子代的等位基因确定突变等位基因，分别算出被检男子和随机男子是孩子生父时，出生该孩子的基因型的概率，并计算出相应的PI值。结果推导出三联体、二联体和孩子失踪案中有突变（包括母亲突变）时PI的计算公式。结论本方法中考虑突变时的PI计算方法易于理解和掌握，在亲权鉴定实践中易于使用。

A New Method for Calculating the Paternity Index in Presence of Mutation

Objective To introduce a method of calculating the paternity index(PI) for autosomal codominant markers when the mutation is encountered.Methods Assuming mutation arises with a mutational probability before an allele segregates and transmits to child with 1/2 chance,the probability of a random man giving an allele to child is the allele frequency in population.Considering only one mutation event in one case,the mutant allele can be determined by comparing the allele between parents and child.Furthermore,the...