Rh phenotype prediction by DNA typing and its application to practice

The complexity of the RHD and RHCE genes, which is the greatest of all bloo d group systems, confounds analysis at the molecular level. RH DNA typing w as introduced in 1993 and has been applied to prenatal testing. PCR-SSP ana lysis covering multiple polymorphisms was recently introduced for the scree ning and initial characterization of partial D. Our objective is to summari ze the accrued knowledge relevant to the approaches to Rh phenotype predict ion by DNA typing, their possible applications beyond research laboratories and their limitations. The procedures, results and problems encountered ar e highly detailed. It is recommended that DNA typing comprises an analysis of more than one polymorphism. We discuss future directions and propose a p iecemeal approach to improve reliability and cost-efficiency of blood group genotyping that may eventually replace the prevalent serology-based techni ques even for many routine tasks. Transfusion medicine is in the unique pos ition of being able to utilize the most extensive phenotype databases avail able to check and develop genotyping strategies.