“…However, caution in performing this test and interpreting the results must be exercised as the PCR-based amplification assays are prone to be contaminated and the genotype determination may not be associated with the antigen expression on the RBCs membrane. Such situations include the detection of genes with a silencing mutation in a location other than that being analysed (point mutation in the GATA box), a gene that is silenced by an alteration of a gene encoding protein with a modifying effect (Rhmod and Rhnull) or the failure to detect hybrid genes (particularly in the Rh and MN blood group systems) (Avent & Reid, 2000;Cartron et al, 1998;Cheng-Han Huang & Blumenfeld, 1995;Huang, 1997;Tournamille, Colin, Cartron, & Le Van Kim, 1995).…”