We developed a polymerase chain reaction-sequence-specific primer (PCR-SSP) technique to screen for hybrid molecules in the MNS blood group in the Thai population using two sets of newly designed primers specific for four GYP(B-A-B) hybrids, GP.Mur, GP.Hop, GP.Bun and GP.HF, and two GYP(A-B-A) hybrids, GP.Vw and GP.Hut. One thousand and forty-one blood samples were tested with human anti-Mi(a) by conventional tube technique, and 598 samples of these were tested by the PCR-SSP technique. Ninety-four samples (9.03%) were strongly positive with human antisera by conventional tube technique. For PCR-SSP test results, the GP.Hut, GP.Mur, GP.Hop, GP.Bun and GP.HF genotypes were amplified with the first set of primers, whereas GP.Vw genotype was amplified with a second set of primers. The GYP(A-B) hybrids (GP. Hil and GP.JL), GYP(A-B-A) hybrids (GP.Nob, GP.Joh and GP.Dane), GYPA, GYPB and GYPE were not amplified by either set of primers. Results of testing 94 Mi(a+) and 504 Mi(a-) by conventional tube technique and PCR-SSP were concordant. This study shows that analysis by PCR-SSP is simple and convenient; therefore, it can be used as an alternative to conventional tube technique for mass screening for MNS hybrids, especially when specific antisera are not available.

Background : Modern bioarray chip technology enables rapid allele determination in a large number of donors by DNA typing when compared to classical serological methods. We analyzed five single nucleotide polymorphisms (SNPs) associated with Dombrock (DO) alleles in blood samples from donors of different ethnic groups, and found new genetic variants. Method : The BeadChip™ technology used primers for a single multiplex PCR reaction, and allele-specific oligonucleotides with variable 3′-terminal nucleotide for elongation-mediated multiplex analysis (eMAPTM) of the DO polymorphisms. Color-encoded beads displaying the elongation probes were assembled into planar arrays of small footprint on semiconductor chips, permitting the instant imaging of fluorescent elongation products from the entire array. Five SNPs of DO blood group antigens DOA/DOB (nt 378 C>T, 624 T>C, 793 A>G), Hy+/Hy− (nt 323 G>T) and Jo(a+)/Jo(a−)(nt 350 C>T) were analyzed simultaneously. Blood samples from a total of 445 donors, comprising of 100 Thai, 69 Jewish, 58 Chinese and 218 random New York City donors were analyzed. Results : As shown in the table below, the predominant diploid allelic combinations observed in all the groups were DOB/DOB followed by DOA/DOB and then DOA/DOA. In the random donor group, we also observed several less prevalent allele combinations: DOB/HY (14.2%), DOB/JO (1.4%), DOA/HY (0.5%), DOA/JO (2.3%), HY/HY (1.4%), JO/JO(1.8%), and HY/JO (0.9%). Interestingly, two novel alleles in trans with the known alleles: DOB/HA (11% in Thai, 2.9% in Jewish, 6.9% in Chinese and 2.8% in random donors), DOA/HA (1.8% in random donors, 1.7% in Chinese and 1.4% in Jewish), DOB/SH (0.5% in random donors) and HY/SH (1.4 % in random donors) were also detected. HA allele is 378T, 624T, 793A (like JO but with 350C). Hemagglutination studies showed that HA, as predicted from the nucleotide at position 793, encoded Doa antigen. SH allele is 378C, 624C, 793C (like HY but with 323G) and is predicted to encode Dob antigen. Conclusion: The BeadChip™ technology facilitated the identification of novel genetic variants, in addition to accelerating blood group typing. Most prevalent DO allele combinations (in %) Ethnic Group DOB/DOB DOA/DOB DOA/DOA Thai 73 14 2 Jewish 52.2 30.4 9 Chinese 79.3 12.1 0 Random 38.5 21.6 11