Santos F R, Epplen J T, Pena S D
Department of Biochemistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
EXS. 1993;67:261-5. doi: 10.1007/978-3-0348-8583-6_23.
Because a son's genotype at a Y-linked locus uniquely specifies his father's genotype at that locus irrespective of the maternal contribution, Y-linked polymorphisms show increased exclusion power over autosomal polymorphisms in paternity cases involving a male child. This advantage is even more obvious when the alleged father is deceased or otherwise unavailable for testing. In this situation, any individual connected by patrilineage to the alleged father may be tested in his place. The usefulness of the Y-linked tetranucleotide repeat locus Y-27H39 in deficiency cases was evaluated in a set of 41 families that had a deceased alleged father and that had been tested at GENE/MG with multilocal and unilocal DNA fingerprinting probes. In sixteen of these cases the proband (child tested) was male and there were male relatives. In the thirteen cases in which paternity was included, Y-27H39 would contribute significantly to the paternity index. In one of three cases in which there was exclusion by fingerprinting probes there was also exclusion by Y-27H39. Thus, Y-27H39 is useful in deficiency paternity cases and will be specially valuable in situations where autosomal polymorphisms have limited power, such as when there is only one male living relative of the deceased father. However, our experience is that Y-linked probes can only be applied in approximately 40% of cases.
由于儿子在Y连锁基因座的基因型能唯一确定其父亲在该基因座的基因型，而与母亲的贡献无关，所以在涉及男童的亲子鉴定案件中，Y连锁多态性比常染色体多态性具有更强的排除能力。当被指控的父亲已去世或无法进行检测时，这种优势更为明显。在这种情况下，可以由任何与被指控父亲有父系血缘关系的人代替他进行检测。在一组41个家庭中评估了Y连锁四核苷酸重复基因座Y - 27H39在缺失情况下的有用性，这些家庭的被指控父亲已去世，并且已经使用多位点和单位点DNA指纹探针在GENE/MG进行了检测。在其中16个案例中，先证者（接受检测的孩子）为男性且有男性亲属。在包含亲子鉴定的13个案例中，Y - 27H39对亲权指数有显著贡献。在通过指纹探针排除亲子关系的3个案例中的1个，也被Y - 27H39排除。因此，Y - 27H39在缺失型亲子鉴定案件中是有用的，并且在常染色体多态性能力有限的情况下，例如当已故父亲只有一个在世的男性亲属时，将特别有价值。然而，我们的经验是Y连锁探针仅能应用于大约40%的案例。
