Chen Ding-Ping, Tseng Ching-Ping, Tsai Shu-Hui, Wang Mei-Chia, Lu Shu-Chuan, Wu Tsu-Lan, Chang Pi-Yueh, Sun Chien-Feng
Department of Laboratory Medicine, Chang Gung Memorial Hospital, Taoyuan County, Taiwan, ROC.
Clin Chim Acta. 2009 Oct;408(1-2):29-33. doi: 10.1016/j.cca.2009.06.042. Epub 2009 Jul 19.
Analysis of short tandem repeats (STRs) has become wide-spread in routine for parentage test. However, the accuracy of STR is sometimes interfered by the presence of microsatellite mutations. Analysis of other DNA markers such as the HV1 and HV2 hypervariable regions of mitochondrial DNA or the Y-STR becomes essential to settle the noncongruence. Owing to the time-consuming nature of these tests, we explored here the use of X-chromosome STR (X-STR) to resolve the paternity and maternity disputes.
At first, the autosomal STR mutation frequencies among 4758 Taiwanese were analyzed. Population data were obtained from randomly selected 99 females and 101 males to setup the X-STR database. Two families with a mismatch of one allele in autosomal STR analysis were subjected to the X-STR test to explore its clinical application.
The STR mutations occurred in all 15 autosomal STR loci with the exception of TH01 and TPOX. The mutation rates could reach as high as 0.106% for the loci of D8S1179 and D18S51. As to the X-STR frequencies, the probability values of exact tests for Hardy-Weinberg equilibrium were 0.1471, 0.0019, 0.0025, 0.1427, and 0.1167 for the loci of DXS7132, DXS981, DXS6789, DXS101, and HPRTB, respectively. In addition, 33 and 34 different haplotypes were revealed for DXS101-DXS6789 and DXS7132-DXS981, respectively. Furthermore, two cases with one allele mismatch in routine parentage test were resolved by performing X-STR analysis.
Typing of X-STR markers is recommended for parentage test when 1 or 2 alleles mismatch is present or when the samples are difficult to be analyzed.
短串联重复序列（STR）分析在亲子鉴定常规检测中已广泛应用。然而，STR的准确性有时会受到微卫星突变的干扰。分析其他DNA标记，如线粒体DNA的HV1和HV2高变区或Y染色体STR，对于解决不一致性变得至关重要。由于这些检测耗时，我们在此探索使用X染色体STR（X-STR）来解决亲子关系争议。
首先，分析了4758名台湾人的常染色体STR突变频率。从随机选择的99名女性和101名男性中获取群体数据以建立X-STR数据库。对两个在常染色体STR分析中有一个等位基因不匹配的家庭进行X-STR检测，以探索其临床应用。
除TH01和TPOX外，所有15个常染色体STR位点均发生了STR突变。D8S1179和D18S51位点的突变率高达0.106%。对于X-STR频率，DXS7132、DXS981、DXS6789、DXS101和HPRTB位点的哈迪-温伯格平衡精确检验概率值分别为0.1471、0.0019、0.0025、0.1427和0.1167。此外，DXS101-DXS6789和DXS7132-DXS981分别显示出33种和34种不同的单倍型。此外，通过进行X-STR分析解决了两例常规亲子鉴定中有一个等位基因不匹配的案例。
当存在1个或2个等位基因不匹配或样本难以分析时，建议在亲子鉴定中进行X-STR标记分型。
