• HGH = human growth hormone;
  • IAT = indirect antiglobulin test;
  • PCR-SSP = PCR with sequence-specific primers.

BACKGROUND: DNA sequencing showed RHD mutations for all weak D phenotypes investigated in a study from Southwestern Germany. Molecular classification of weak D offers a more reliable basis than serotyping and is relevant for optimal D transfusion strategies.

STUDY DESIGN AND METHODS: Sequence-specific primers were designed to detect weak D types 1 to 5 and the partial D phenotype HMi in a modular set for conventional PCR analysis. Alternatively, all reactions were multiplexed into a single tube, and the products were identified after automated capillary electrophoresis by their size and fluorescence. Weak D phenotype samples from 436 donors in the Tyrol (Austria) and Northern Germany were investigated by PCR.

RESULTS: More than 90 percent of the weak D types identified by PCR represented type 1, 2, or 3. The distribution among the common types varied between the Tyrol and Northern Germany (p<0.0001). Three new RHD alleles were identified.

CONCLUSION: A PCR method of detecting the common weak D types was validated. This PCR system introduces a simple and rapid tool for routine DNA typing of weak D samples. The results confirmed that all weak D phenotype samples identified by current serologic criteria carry altered D proteins.