Molecular organisation of Kell (KEL) red blood cell variants among voluntary blood donors at the National Blood Grouping Testing Laboratory, Kenya

A variant is an alternative nucleotide located at a specific region of a gene. 48 genes encode for human red cell blood group systems. Variants within these genes encode for alleles, which can be highly polymorphic. The blood group gene loci jointly display all types of inherited variants to include single nucleotide variants (SNVs), insertions/deletions (indels), and structural variants. In Africa, there is limited information on the red cell variants. The aim of the study was to determine the incidence of Kell red blood cell variants among the Kenyans. Blood donor’s samples that were used for routine grouping process were identified for this study. Next generation sequencing method was employed to predict the Kell red cell variants in blood donor samples. Descriptive statistics was applied and the result was presented in form of tables. The study reveals that Kell system has six variants with two major phenotypes and genotpes. The most common phenotype genotyped was KEL2 (KEL*02/KEL*02) 79% (85/108) followed by KEL2 KEL6 KEL7 (KEL*02.06/KEL*02) 16.7% (18/108). The rest were found to be of low frequency and all were associated with KEL2. The study recommends an extended study with a large sample size and introduction of extended phenotyping to aid Kell antigens identification in the donor population.