Deficient Paternity Test
Definition
Paternity inferred from the alleged father's relatives (grandparents, siblings) when the alleged father himself is unavailable or deceased.
- Tested relatives
- Grandparents, siblings of alleged father
- Used when
- Alleged father unavailable or deceased
- Context
- Disputed paternity testing in India
Common questions
Why is a deficient paternity test statistically weaker?+
Testing relatives instead of the alleged father directly means the genetic link is inferred through an extra generation or lateral relationship, which lowers the statistical power of the result compared to a direct father-child comparison.
When is a deficient paternity test the only option available?+
When the alleged father has died, disappeared, or otherwise cannot be sampled, so investigators rely on his parents or siblings to reconstruct part of his genetic profile.
Related terms
- Combined Paternity Index (CPI)
- The product of all individual paternity indices across all marker systems tested. Assumes independence of the marker systems. The CPI is a...
- Exclusion
- The categorical conclusion that one or more examined features are clearly inconsistent in a way that cannot be explained by projection angle,...
- Inclusion
- All obligate alleles are accounted for. Inclusion is probabilistic, never absolute, and is reported as a CPI plus probability of paternity.
- Motherless Paternity Test
- Paternity analysis where the mother's sample is unavailable. CPI thresholds are raised because the obligate paternal allele cannot be inferred from the...
- Mutation Rate
- STR loci mutate at roughly 0.001 to 0.005 per generation. A single one-step mismatch is typically scored as a possible mutation, not...
- Obligate Paternal Allele
- The allele in the child's genotype that did not come from the mother and therefore must have come from the biological father.
- 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...
- Presumption of Legitimacy
- Statutory presumption that a child born during the continuance of a valid marriage is the legitimate child of the husband. Rebuttable only...
- Probability of Paternity (W)
- The posterior probability that the alleged father is the biological father, calculated from the CPI and a prior probability using Bayes' theorem....