Exclusion | DNA Testing Glossary

In DNA relationship testing, an exclusion is a result indicating that the tested individual is not the biological relative in question. In a paternity test, an exclusion means the alleged father is not the biological father of the child. The lab reaches this conclusion when the child's DNA does not match the alleged father's DNA at multiple genetic markers — typically three or more loci showing mismatches. An exclusion is absolute and reported with a probability of 0%. There is no gray area. False exclusions are rare in properly conducted STR-based tests. A single mismatch at one locus, on its own, does not automatically result in an exclusion — it may indicate a mutation, which the lab will investigate further.

Related Terms

Inclusion, Probability of Paternity, Mutation, Allele, Combined Paternity Index

Source

AABB — Guidance for Standards for Relationship Testing Laboratories