When trying to establish paternity, there are a few DNA test options available. All the options we go over, can be used for legal court admissible DNA testing or just for peace of mind.
Father and Child Paternity Test
The very best way to establish paternity of a child is to test the father and child. DNA testing with a father and child is the most direct and straight forward test. In each genetic marker, there are 2 alleles. One allele comes from the child’s mother and the other allele comes from the child’s father. This means that the father and child must match with 1 of the 2 alleles in each loci.
Grandparents Paternity Test
The 2nd best way to establish paternity of a child is to test the child and both of the paternal grandparents. The father received all of his DNA from his parents. Therefore, on each loci, the child would match with either the grandmother or the grandfather with 1 allele. This test is used to prove if a son to the alleged paternal grandparents is the father to the child.
Male Lineage DNA Test with Y Chromosomes
The 3rd best way to establish paternity to a child is dependent on if the child is a male or a female. If the child is a male, it is much easier for special relationship testing to be performed if there is a male relative to test along with the male child. This can include a paternal uncle to the child, a paternal grandfather to the child or even a brother sharing the same father to the child.
The reason testing 2 males relatives is easiest is because males have an extra advantage because of their Y chromosomes. Y chromosomes are passed directly through the male line. They are passed from grandpa to his male children. Then those male children pass them along to their own male children. Y chromosomes are an exact match through the male lineage.
Sibling Paternity Test
The 4th best way to establish paternity to a child is to test paternal siblings. As stated above, if the child at question is a male, it is ideal to test another male child. However, if either child is a female, we can still perform sibling DNA testing. To prove paternity using siblings, you will need to choose if the test needs to be ran as a full sibling versus half sibling. Or the other option is half sibling versus unrelated.
If the 2 individuals testing have the same mother and want to know if they also share the same father, they would need the full sibling test. On the contrary, if the individuals testing do not have the same mother, they would need the half sibling test.
Aunt/Uncle Paternity Test
Finally, the 5th best way to establish paternity to a child is to test aunts or uncles. As stated above, if the child at question is a male, it is ideal to test the paternal uncle. However, if aunts are the only paternal relatives available, the test can still be performed. This type of tests determines if the full brother to the aunt or uncle testing could be the father to the child. The aunt or uncle must be a full sibling to the alleged father to do the testing.
As you can see, the very best DNA test to prove paternity is using the father and child. In some instances that is not an option. Maybe the father is unable or unwilling to participate in a paternity test. If that is the case, we can test other paternal relatives to establish paternity.