Molecular basis of RHD variants among RHD negative blood donors in Malaysia: a cross-sectional study / Safura Ramli

Rhesus blood group system consists of a few variants such as partial D, Weak D and DEL phenotype. Rhesus genotyping on those phenotypes has been intensively studied and found vary in different populations. To date, there is a paucity of data for DEL and weak D phenotype in Malaysian population, thus the purpose of this study was to determine the molecular basis and the prevalence of DEL and weak D phenotype in Malaysia. A total of 322 RhD negative blood samples were collected from the blood donors at National Blood Centre, Kuala Lumpur Malaysia. Serological and molecular analyses was performed, and positive samples from the RHD gene amplification were further tested for the the presence of RHD 12227A allele by using SSP-PCR to detect DEL phenotype. Meanwhile, a specific kit was used to determine the the subtype of weak D. Among the 322 blood samples, 21 samples (6.5%) were confirmed as DEL phenotype by the presence ofRHDJ227A allele and two samples positive for weak D type 15 (0.6%). Majority of DEL samples came from Malays donors (n=10), followed by Chinese (n=6) and Indians (n=5), whereas all weak D samples came from Chinese ethnic. In conclusion, the prevalence of DEL and weak D phenotype is lower in Malaysia compared to other Asian countries. This study added to the understanding of molecular basis underlying DEL and weak D phenotypes in our population and provided useful information for adopting suitable genotyping strategies in future.