False Exclusion
Definition
An incorrect serological finding that excludes a true biological parent. Causes include chimerism (two cell populations in one individual), rare antigen variants, technical error in typing, and undisclosed blood transfusion altering the sample's antigen profile.
- Context
- Serological parentage or kinship testing
- Effect
- Incorrectly excludes a true biological parent
- Cause: chimerism
- Two distinct cell populations present in one individual
- Other causes
- Rare antigen variants, technical typing error, undisclosed transfusion
Common questions
Why has DNA profiling largely replaced blood group typing for parentage testing?+
Blood group systems have a limited number of antigen markers and are vulnerable to the false-exclusion mechanisms above, while STR-based DNA profiling examines many more independent loci with far lower false-exclusion rates, making it the current standard for parentage and kinship determinations.
How does an undisclosed blood transfusion cause a false exclusion?+
A recent transfusion can temporarily introduce donor red cells carrying a different antigen profile into the tested individual's blood sample, so the typing result reflects a mixture that does not match the person's own inherited antigens, leading to an apparent, incorrect exclusion of a true relative.
Related terms
- Exclusion
- The categorical conclusion that one or more examined features are clearly inconsistent in a way that cannot be explained by projection angle,...
- Exclusion Probability (PE)
- The proportion of unrelated men in the relevant population who would be excluded as fathers of a child with the observed maternal...
- Non-Exclusion (Inclusion)
- A finding that the alleged parent's blood group profile is compatible with parentage. Non-exclusion does not prove parentage: it means only that...
- Paternity Index (PI)
- A likelihood ratio that compares the probability of the observed serological profile if the alleged father is the biological father to the...
- Phenotype
- The observable serological result for a blood group system, determined by which antigens are present on the red cell surface. Two people...