DNA paternity testing

DNA paternity testing uses DNA profiles to determine whether an individual is the biological parent of another individual. Paternity testing can be essential when the rights and duties of the father are in issue, and a child's paternity is in doubt. Tests can also determine the likelihood of someone being a biological grandparent. Though genetic testing is the most reliable standard, older methods also exist, including ABO blood group typing, analysis of various other proteins and enzymes, or using human leukocyte antigen antigens. The current paternity testing techniques are polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Paternity testing can now also be performed while the woman is still pregnant from a blood draw.^[1][2]

DNA testing is currently the most advanced and accurate technology to determine parentage. In a DNA paternity test, the result (called the 'probability of parentage)^[3] is 0% when the alleged parent is not biologically related to the child, and the probability of parentage is typically 99.99% when the alleged parent is biologically related to the child. However, while almost all individuals have a single and distinct set of genes, rare individuals, known as "chimeras", have at least two different sets of genes. This can lead to complications during DNA analysis, such as false negative results if their reproductive tissue has a different genetic makeup from the tissue sampled for the test.^[4]