父母基因型重构在复杂同胞亲缘关系鉴定中的应用

Application of parental genotypes reconstruction in determination of complex sibship

目的为识别参考个体中存在的可疑半同胞,在没有父母遗传信息情况下,解决可疑同胞与参考个体之间的全同胞及半同胞复杂亲缘关系鉴定问题。方法通过检测常染色体并计算参考同胞之间的全同胞指数(Full-sib Index,FSI)及进行IBS评分(Identity by states score),并检测Y染色体以进一步明确参考同胞中的可疑半同胞;根据参考同胞信息构建亲代X染色体及常染色体基因型,并利用已识别的参考半同胞信息推导母亲常染色体基因型。结果确定了参考个体中一名半同胞,最后在没有线粒体技术辅助的情况下,不仅排除了评估对象与参考个体之间的全同胞关系,也明确否定了半同胞关系。结论充分利用参考个体(本案中的全同胞与半同胞)遗传信息,能为复杂亲缘鉴定提供有力的判定依据。

Objective To distinguish a half-sib from the reference individuals,and solve the problem of complex kinship where both full-sibship and half-sibship are necessary to analyze in the absence of parental information.Methods We estimated the full-sib index（FSI） and Identity by states（IBS） score between the reference individuals after the detection of autosomes.Simultaneously,the Y chromosome was examined for a further confirmation for the suspicious half-sib.The parental genotypes of X chromosomes and autosomes were reconstructed using the referable sibs;moreover,parts of maternal genotypes of autosomal markers were also deduced taking advantage of the identified half-sib.Results A half-sib was recognized from the reference full-sibs;the full-sibship,as well as the half-sibsip,was excluded clearly without the aid from mitochondrial DNA Typing.Conclusion The analysis of the complex kinship can be more powerful provided the genetic data of reference individuals,such as the full-sibs and half-sib in this case,is fully taken advantage of.