Disputed parentage due to exchanged babies solved by HLA

Area of Science:

• Forensic Genetics
• Immunogenetics
• Human Genetics

Background:

• Disputed parentage cases involving newborns require reliable methods for identification.
• Traditional blood group and genetic marker systems have limitations in definitively excluding or including individuals in parentage cases.

Purpose of the Study:

• To investigate the effectiveness of various genetic markers, including HLA phenotypes, in resolving a suspected newborn exchange case.
• To compare the discriminatory power of HLA typing with other genetic markers for parentage testing.

Main Methods:

• Blood samples were collected from two suspected exchanged newborn girls and their respective families.
• Genetic analysis included ABO, Rh, MN blood groups, isoenzymes (ADA, AcP1, GLO, PGM1, AK1), haptoglobin (Hp), and Human Leukocyte Antigen (HLA-A and B) phenotypes.
• Statistical calculations were performed to determine the odds of parentage based on the observed phenotypes.

Main Results:

• Both baby girls were excluded from their initially suspected families based on multiple genetic markers, including ADA, GLO, PGM1, AK1, Hp, and HLA.
• The phenotypes of each baby girl were consistent with the parents of the other family, suggesting a swap.
• HLA testing provided significantly higher statistical odds (2-3 orders of magnitude greater) for exclusion/inclusion compared to other marker systems, with overall odds reaching 1.7 x 10^12:1 for the simultaneous misattribution of both children.

Conclusions:

• Human Leukocyte Antigen (HLA) typing is a highly powerful and reliable tool for resolving disputed parentage, particularly in cases of suspected newborn exchanges.
• HLA testing offers superior discriminatory power compared to traditional blood group and other genetic marker systems.
• The study demonstrates the critical role of advanced genetic testing in ensuring accurate infant identification and resolving complex familial disputes.