paternitytest

A paternitytest, or paternity test, is a genetic test used to determine whether a man is the biological father of a specific child. The test compares DNA profiles from the child and the alleged father, and often the mother, to assess inherited genetic markers. The most common approach analyzes autosomal short tandem repeat (STR) markers across the genome. Laboratories typically test 15 to 20 loci to produce a statistical estimate of paternity.

Results are reported as a probability of paternity, often accompanied by a paternity index or a combined paternity index. An exclusion occurs when a sufficient number of markers are inconsistent with the alleged father, indicating he cannot be the biological father. An inconclusive result may occur if data are insufficient or if rare mutations affect marker matching. When the mother’s DNA is included, interpretation is generally clearer and less prone to inconclusive outcomes.

Samples are usually collected from cheek swabs or saliva. In legal contexts, chain-of-custody procedures ensure samples are properly handled and the testing is admissible in court; the test is then referred to as a legal or court-admissible paternity test. Direct-to-consumer tests are available without a medical professional, but their results may not be legally admissible without proper chain-of-custody documentation.

Uses include resolving questions of paternity for child support, inheritance, immigration, or personal knowledge. Limitations include the possibility of mutations at DNA loci, sample contamination, or insufficient data, and privacy and ethical considerations surrounding genetic information.