What kinship can DNA identify?

At present, the kinship identification carried out by forensic material evidence specialty includes the following categories:

1. Routine paternity test: This is the most needed paternity test at present, including paternity test of parents and children (also known as triplets) and father and son (or mother and son) (also known as twins). The accuracy of this recognition can reach 99.999999%.

2. Identification of intergenerational kinship: This identification refers to the identification of kinship between great-grandparents, grandparents, great-grandchildren and grandchildren.

It also includes simple paternal kinship identification, such as confirming the kinship between great-grandfather, grandfather, great-grandson and grandson, and simple maternal kinship identification, such as confirming the kinship between great-grandmother, grandmother, granddaughter and great-granddaughter.

3. Difficult to identify kinship: In addition to the above two categories, there are still some difficulties in identifying kinship, such as the identification of brothers and sisters (brothers, sisters, brothers and sisters) with suspicious parents, the identification of kinship between uncles and nephews, and the identification of kinship between uncles and nieces.

Extended data:

Paternity identification refers to the identification of the biological relationship between the defendant's parents and children by using the theory and technology of biology, genetics and related disciplines according to the genetic law of genetic traits between offspring and parents.

The cases involved include: disputes over the support of children born out of wedlock, disputes over property inheritance, identification of biological children caused by the wrong delivery room in the hospital, and claims for abducted and separated children.

Paternity identification is mainly based on the genetic law of simple genetic traits other than human blood type and blood type. Genetic traits are controlled by genes located on chromosomes in the nucleus, and individual characteristics are passed on to offspring through gene transmission between parents and offspring.

The principle of paternity test:

The theoretical basis for judging biological kinship is Mendel's inheritance of separation phenomenon. According to this rule, when gamete cells are formed, pairs of alleles are separated from each other and enter their respective gamete cells respectively.

Sperm and egg cells are fertilized to form offspring, and the two genomes of the child come from mother and father; Therefore, one allele of the same pair comes from the mother and the other from the father. If the identification results conform to this law, biological relationship is not excluded; If not, biological relationship (except variation) will be ruled out.

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