Fukuta Mamiko, Gaballah Mohammed Hassan, Kato Hideaki, Aoki Yasuhiro
Department of Forensic Medicine, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya 467-8601, Japan.
Department of Forensic Medicine, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya 467-8601, Japan.
Leg Med (Tokyo). 2018 May;32:9-18. doi: 10.1016/j.legalmed.2018.02.002. Epub 2018 Feb 12.
X-chromosomal short tandem repeats (X-STRs) are useful for personal identification and kinship tests. However, it has not yet been fully established how to incorporate linkage and linkage disequilibrium (LD) into the calculation of the likelihood ratio (LR). In this paper, we describe a simple calculation method of LR for X-STRs that incorporated linkage, LD, and mutations. Initially, Japanese population data of 27 X-STRs (DXS6807, DXS9902, DXS6795, DXS6810, DXS10076, DXS10077, DXS10078, DXS10162, DXS10163, DXS10164, DXS7132, DXS981, DXS6800, DXS6803, DXS6809, DXS6789, DXS6799, DXS7424, DXS101, DXS7133, GATA172D05, DXS10103, HPRTB, GATA31E08, DXS8377, DXS10147, and DXS7423) were collected from 748 unrelated individuals to estimate the influence of LD. Significant LD was observed on six pairs of loci. Subsequently, using the population data, a simulation study was performed to evaluate the validity of the present calculation method for LR in cases of father-daughter, full-sisters, paternal half-sisters, maternal half-sisters, and unrelated pairs of females (FD, FS, PHS, MHS, and UR, respectively). As a result, the distribution of LR among FD was completely separated from that among UR. In the sibship test, 98.6% of FS and 98.0% of PHS surpassed the maximum value of UR in combined LR. Even in the FS versus MHS setting, 60.5% of FS had a higher LR than any MHS. We conclude that the present model is powerful in discriminating the relationship and is able to obtain a reasonable LR with fewer computations.
X染色体短串联重复序列（X-STRs）可用于个人识别和亲属关系鉴定。然而，如何将连锁和连锁不平衡（LD）纳入似然比（LR）的计算尚未完全明确。在本文中，我们描述了一种针对X-STRs的LR简单计算方法，该方法纳入了连锁、LD和突变。首先，从748名无关个体中收集了27个X-STRs（DXS6807、DXS9902、DXS6795、DXS6810、DXS10076、DXS10077、DXS10078、DXS10162、DXS10163、DXS10164、DXS7132、DXS981、DXS6800、DXS6803、DXS6809、DXS6789、DXS6799、DXS7424、DXS101、DXS7133、GATA172D05、DXS10103、HPRTB、GATA31E08、DXS8377、DXS10147和DXS7423）的日本人群数据，以估计LD的影响。在六对基因座上观察到显著的LD。随后，利用这些人群数据进行了模拟研究，以评估本计算方法在父女、全姐妹、同父异母姐妹、同母异父姐妹以及无关女性对（分别为FD、FS、PHS、MHS和UR）情况下LR的有效性。结果，FD组中LR的分布与UR组完全分开。在亲属关系测试中，98.6%的FS和98.0%的PHS在联合LR中超过了UR的最大值。即使在FS与MHS的比较中，60.5%的FS的LR高于任何MHS。我们得出结论，本模型在区分亲属关系方面很强大，并且能够以较少的计算获得合理的LR。
