A paternity testing method based on fetal cell-free DNA in the peripheral blood of pregnant women

Abstract

The invention relates to the technical field of biogenetics, in particular to a paternity identification method based on fetal free DNA in the peripheral blood of pregnant women. The detection sample used in the paternity testing method based on fetal free DNA in the peripheral blood of pregnant women is easy to obtain, effectively avoiding unnecessary medical risks to pregnant women or fetuses; at the same time, the exclusion index X provided by the present invention 1 And the established paternity test evidence value evaluation model (formula IV, formula V, formula VI, etc.) can not only effectively avoid misjudgment, but also has higher identification efficiency; in addition, the paternity test method is simple to operate and has high analysis efficiency; Therefore, the test result obtained by implementing the paternity testing method provided by the present invention can be further used as an effective legal evidence, thereby being widely used in judicial paternity testing and other application fields.

Description

technical field [0001] The invention relates to the technical field of biological genetics, in particular to a paternity identification method based on fetal free DNA in the peripheral blood of pregnant women. Background technique [0002] In the prior art, the paternity test before delivery of the fetus mainly includes two schemes: [0003] The first option is: after the fetus reaches a certain gestational age (at least 13-14 weeks), prenatal samples are obtained through amniocentesis, or chorionic villus biopsy, etc., and the traditional method based on short tandem repeat (STR) genetic The labeled forensic paternity test kit is used for paternity test, and the biological father of the fetus is determined according to the judicial test technical specification "Paternity test technical specification" (SF / Z JD0105001-2016). The "Technical Specifications for Parentage Test" provides a method for calculating the parentage index using the traditional STR, and the parentage ind...

AI Technical Summary

Problems solved by technology

Therefore, when using NGS technology to detect a low proportion of DNA in a mixed sample, it depends on the depth of sequencing coverage. For example, when detecting a low proportion of 1% DNA, the sequencing depth of NGS should be at least 200 times; When it is lower, it may be due to insufficient sequencing depth that the paternal allele should be detected but not detected, thus forming a "false" homozygous result of the fetal maternal allele at such a site, while multiple Such sites will inevitably lead to misjudgment of the final paternity test results

[0008] In addition to the above-mentioned technical defects, the existing NGS technical scheme itself lacks the research on the statistical model of possible genetic evidence value indicators; parental judgments are made only based on the number of so-called incompatible loci based on experience. On the one hand, there are misunderstandings. The possibility of judging, the more important aspect is that due to the lack of a scientific evidence value evaluation system, its test results are also difficult to be used as an effective legal evidence

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