Genotyping Rhesus, Kidd, Dombrock and Colton blood group systems in sickle cell patients in Uganda

Abstract

Sickle Cell Disease (SCD) is one of the most prevalent genetic blood disorders. Blood Transfusion (BT) has remained a cornerstone in its management but exposes a recipient to RBC alloimmunization. In Uganda an alloimmunization rate of 6.1% was reported in 2010 and thus the aim of this study was to investigate the possible causes based on distribution of certain blood groups between the donor and SCD population. A case-control study was undertaken so as to assess genetic diversity of; RhD negative donors, Kidd, Dombrock and Colton blood group systems in sickle cell patients at the Mulago Sickle Cell Clinic and the blood donors at the Nakasero Blood Bank. A total of two hundred (200) blood samples from serologically typed RhD negative blood donors were obtained from Nakasero blood bank to assess the diversity of RhD negativity and a total of three hundred ninety five (395) blood samples from both sickle cell patients (cases) and blood donors (controls) were collected from Mulago sickle clinic and Nakasero blood bank respectively to assess the genetic diversity of Kidd, Dombrock and Colton.The study revealed that the most prevalent cause of RhD negativity was due to the presence of the pseudo gene (48%) followed by complete deletion of the D gene (33%); deletion of exons 3,4,5,& 7(12%); deletion of exons 3,4,&7(2.5%); deletion of exon 5 (1.5%); deletion of exon 4(1%); deletion of exons 3&4(0.5%); deletion of exons 4&7(0.5%) from the D gene. The remaining 2(1%) individuals had presence of all 6 exons. It was also found that, the prevalent genotype for Kidd, Dombrock and Colton was the heterozygote i.e.; JK1/JK2, DO1/DO2, and CO1/CO2 respectively. In conclusion, our study reported that the cause of RHD negativity in the study population was majorly due to presence of a pseudo gene and that after carrying out statistical data analysis, there was no significant difference between the alleles of the Kidd, Dombrock and Colton in the Sickle Cell Disease group and control group.