A cross-sectional pilot study to estimate the frequency of minor blood group alleles and phenotypes in RhD-negative North Indian blood donors by DNA microarray analysis.

Introduction: There are scarce data on Indian blood donors with respect to blood group phenotypes using molecular diagnostic modalities. Hence, we planned to estimate frequencies of blood group alleles/phenotypes using DNA microarray analysis in the north Indian RhD-negative blood donor population. With this initial pilot study, we plan to expand it to our entire donor population.

Methodology: The cross-sectional prospective study was conducted on 50 Indian blood donors (O RhD negative), to study the blood group genotype frequency. Genotyping for the most relevant red blood cell antigens (Rh, Kell, Duffy, Kidd, MNS, Lutheran, and Dombrock) was done using Bioarray Precise Type^HM Human Erythrocyte Antigen BeadChip kit containing probes directed to polymorphic sites.

Results: In the Rh system, the most common alleles were RHCE*e/RHCE*e (98%) and RHCE*c/RHCE*c (80%). Phenotype K-k+ (genotype- KEL*02/KEL*02) was seen in 98% of samples, Js(a-b+) (KEL*02.07/KEL*02.07) was detected in 98% (49/50) of the samples tested. Jk(a + b+) (JK*01/JK*02) was the most common phenotype (48%) in the Kidd blood group system. In MNSs system, M+N+ (GYPA*01/GYPA*02) 44% and S+s+U+ (GYPB*03/GYPB*04) 34% were the most common phenotypes detected.

Conclusion: This pilot study shows the feasibility of genotyping a Northern Indian donor population. To the best of our knowledge, it is the first study on molecular blood grouping in Indian blood donors using the Bioarray platform.