nonpaternity

Nonpaternity refers to a situation in which the social or presumed father of a child is not the biological father. In everyday use, paternity can be established by social or legal roles, while biological paternity concerns direct genetic relationship. Nonpaternity events may be identified before or after birth, or through genetic testing conducted for medical, legal, or personal reasons.

Common contexts include assisted reproduction or donor insemination where the donor is not disclosed; extramarital or nonmarital paternity; changes in family records; or errors in documentation. Nonpaternity may be discovered when biological relatives are tested for medical reasons or in child support or custody disputes.

Detection typically relies on DNA analysis. Standard autosomal DNA paternity testing compares multiple genetic markers between the child and the alleged father to determine inclusion or exclusion of paternity, with high accuracy. Y-chromosome testing can assess paternal lineage. Tests are performed by accredited laboratories and require informed consent and privacy protections. Results are probabilistic and reported as likelihoods rather than absolute proof in some cases.

Implications include legal consequences such as child support, custody, and inheritance, as well as social and emotional effects on the child and families. Ethical considerations include privacy, consent for testing, potential stigma, and the right to know one’s biological relationships. Practices and laws regarding paternity testing vary by jurisdiction.

See also: Paternity; Paternity testing; Misattributed paternity; Genetic genealogy; Donor conception.