Exclusion Probability (PE)
Definition
The proportion of unrelated men in the relevant population who would be excluded as fathers of a child with the observed maternal and child phenotypes. Computed for each system separately, then combined as a cumulative figure across all tested systems.
- Symbol
- PE
- Measures
- Proportion of unrelated men excluded as fathers per system
- Combination
- Cumulative figure across all tested systems
- Field
- Blood group typing in paternity and kinship testing
Common questions
Why is exclusion probability calculated per system before being combined?+
Each blood group system has its own allele frequencies and discriminating power, so calculating PE separately lets analysts see which systems contribute most, then combine them into a cumulative exclusion probability that reflects the whole panel's power.
Does a high cumulative PE prove paternity when a man is not excluded?+
No. It shows the test panel is powerful at excluding unrelated men, but a man who is not excluded is only consistent with being the father, and a separate paternity index or likelihood calculation is needed to state the probability of paternity.
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,...
- False Exclusion
- An incorrect serological finding that excludes a true biological parent. Causes include chimerism (two cell populations in one individual), rare antigen variants,...
- 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...