Evaluation of ABO and Lewis genotypes using primer extension preamplification

Area of Science:

• Forensic Science
• Genetics
• Serology

Background:

• Serologic blood typing methods face challenges with variant ABO and Lewis negative samples.
• Accurate blood group determination is crucial in forensic and clinical settings.
• DNA analysis offers a complementary approach to resolve typing discrepancies.

Purpose of the Study:

• To evaluate the utility of DNA analysis, specifically Polymerase Chain Reaction (PCR) with and without Primer Extension Preamplification (PEP), for ABO and Lewis genotyping.
• To assess the minimum DNA quantity required for accurate genotyping.
• To determine if combined serologic and DNA testing improves blood grouping accuracy.

Main Methods:

• DNA was extracted from bloodstains and subjected to PCR for ABO and Lewis genotyping.
• Primer Extension Preamplification (PEP) was employed to amplify limited DNA samples (1-3 ng).
• Results from PCR with and without PEP were compared, and cross-checked with serologic typing.

Main Results:

• Accurate ABO and Lewis genotyping was achieved using PCR with as little as 1-3 ng of DNA.
• PCR products with or without PEP treatment yielded identical genotyping results.
• Simultaneous serologic and PCR testing allowed for cross-checking and discrepancy investigation.

Conclusions:

• DNA analysis, particularly PCR with PEP, is a valuable tool for accurate ABO and Lewis blood grouping, especially for challenging samples.
• The PEP method is effective for amplifying limited DNA quantities for genotyping.
• Combining serologic and DNA testing enhances the reliability of blood group determination and minimizes typing errors.