Blood group typing by molecular techniques : application to immunohaematology
The initial aim was to establish conventional DNA typing technology for blood group typing using cell derived genomic DNA material from donors. Accordingly, blood samples were collected from 200 healthy, randomly selected, Aberdeen Regional blood donors. The DNA extracted from these samples was used to develop and validate PCR assays for RHD, RHDPsi, RHC/c, KEL1 and KEL2, Fya and Fyb and ABO blood group alleles. All samples were also phenotyped serologically for RH, KEL, Duffy and ABO blood groups. Complete concordance was observed between phenotype and genotype. The developed RHD, RHDPsi and Fya and Fyb genotyping assays were then applied to study the molecular basis of blood groups in a cohort of 170 native Saudi donors. This study demonstrated there was no significant difference between the Saudi and Scottish (Caucasian) populations with respect to the RHD or RHDPsi blood groups. However, a significant difference was recorded with respect to the molecular basis of the FY blood group in which 30.6% of the Saudi donors were typed as Fy/Fy. The Fyx allele was also observed in this cohort. Further study of the Scottish blood donor population was performed to define the molecular basis of Weak D in 58 SNBTS (Scottish National Blood Transfusion Services) blood donors. Weak D types 1 and 2 represented more than 95% of all Weak D types tested in this study. Of the rest, nine samples were typed as DVI type II, one sample typed as DVII, one sample typed as DVa type II and a new partial D was identified in one sample to be lodged with the Genbank DNA database. In the second part of the project, the overall aim was to develop fetal DNA typing from maternal plasma.