Krawczak Michael
Institut für Medizinische Informatik und Statistik, Christian-Albrechts Universität Kiel, Brunswiker Strasse 10, 24113 Kiel, Germany.
Forensic Sci Int Genet. 2007 Jun;1(2):111-4. doi: 10.1016/j.fsigen.2007.01.014. Epub 2007 Feb 27.
Use of X-chromosomal markers for kinship testing is meaningful if the identical-by-descent allele sharing probabilities of at least two individuals involved in the case differ under the different hypotheses made about the composite relationships. In this situation, optimal decision making about one or the other hypothesis should be based upon the likelihood ratio of the genotype data obtained. When more than one X-chromosomal marker is being used, this implies that the patterns of linkage and linkage disequilibrium between the respective loci have to be taken into account. Otherwise, the evidence extracted from the data by means of the likelihood ratio may be misleading. Exact likelihood calculations on complex pedigrees can be performed using available software such as, for example, the "LINKAGE" programmes widely used in genetic epidemiology. The required genetic maps can be created using physical location information available in public databases.
如果针对复合关系所做的不同假设下，案件中至少两个涉案个体的同源等位基因共享概率存在差异，那么使用X染色体标记进行亲缘关系检测就具有意义。在这种情况下，对于某一假设或另一假设的最优决策应基于所获得的基因型数据的似然比。当使用多个X染色体标记时，这意味着必须考虑各个位点之间的连锁和连锁不平衡模式。否则，通过似然比从数据中提取的证据可能会产生误导。对于复杂系谱，可以使用遗传流行病学中广泛使用的“LINKAGE”程序等现有软件进行精确的似然计算。所需的遗传图谱可以利用公共数据库中可用的物理位置信息来创建。
