Background: Almost all relationship analysts now use molecular (DNA) tests to obtain necessary genetic information, yet older blood group tests remain valid. Circumstances may provide blood test results from old reports to avoid trying to sample DNA from inaccessible sources.
Case study: A mother recently claimed that a deceased man (alleged father [AF]) sired her child. Insurance investigation recovered two paternity test reports from an AABB-accredited laboratory. The 16- and 18-year-old reports employed blood groups and protein polymorphisms to exonerate two different men. One report contained the multilocus phenotypes of the AF and the other contained the phenotypes of the mother and child at the same loci. A new case was synthesized from the old reports.
Results: Genetic inconsistencies (three direct and one indirect) were demonstrated among the nine loci that had been typed in both the AF and the mother-child pair.
Conclusion: New relationship tests may be reconstructed from phenotypes reported before the molecular test era. This approach avoids exhumation and other problematic methods of specimen retrieval.