FREQUENCY OF VARIOUS RH ANTIGENS IN DAMMAM EASTERN PROVINCE, SAUDI-ARABIA

Objectives: To study gene frequency of RhD in Saudis in Dammam region and the common Rh phenotypes. Materials and methods: Seven thousand an d ninety three blood samples from Saudi male blood donors were evaluat ed for presence or absence of D antigen. D negative antigen samples we re tested for Rh phenotypes. In addition, another group of 616 Rh posi tive samples (416 Saudi male donors and 200 Saudi female OPD patients) were tested for Rh phenotype. All tests were done in Regional Laborat ory & Blood Bank, Dammam using standard antisera. Results: The frequen cy of Rh negative blood group in Dammam region was found to be 9.18%. The gene frequency for ''D'' was calculated as 0.7. Rh phenotypes pres ent in decreasing order of frequency were R(1)r, (RR1)-R-1,R(0)r, R(2) r, rr, (RR2)-R-1, (RR2)-R-2, (RR2)-R-1, r(1)r, (RRz)-R-z, (RRz)-R-2, r '' r, r'r ''. Conclusion: Rh negative frequency is more than previous ly reported. RO and Rz haplotypes are more common while r is less comm on compared with white European population.