TITLE:
Diversity and Frequencies of HLA Class I and Class II Genes of an East African Population
AUTHORS:
Trevor A. Peterson, Thomas Bielawny, Philip Lacap, Rae-Anne Hardie, Christina Daniuk, Lillian Mendoza, Subotheni Thavaneswaran, Tony Kariri, Joshua Kimani, Charles Wachihi, Maboku Kimani, Terry Blake Ball, Francis A. Plummer, Ma Luo
KEYWORDS:
HLA-A, HLA-B, HLA-C, HLA-DPA1, HLA-DPB1, HLA-DQA1, HLA-DQB1, HLA-DRB1, HLA Frequencies, HLA Class I, HLA Class II, East African
JOURNAL NAME:
Open Journal of Genetics,
Vol.4 No.2,
April
10,
2014
ABSTRACT: Human Leukocyte
Antigens (HLAs) play an important role in host immune responses to infectious
pathogens, and influence organ transplantation, cancer and autoimmune diseases.
In this study we conducted a high resolution, sequence-based genotyping of HLA
class I and class II genes of more than 2000 women from Kenya, eastern Tanzania
and southern Uganda around Lake Victoria and analyzed their allele, phenotype
and haplotype frequencies. A considerable genetic diversity was observed at
both class I and II loci. A total of 79 HLA-A, 113 HLA-B, 53 HLA-C, 25 HLA-DPA1,
60 HLA-DPB1, 15 HLA-DQA1, 44 HLA-DQB1 and 38 HLA-DRB1 alleles have been
identified. The most common class I alleles were A * 02:01:01 (10.90%), B *
58:02 (8.79%), and C * 06:02:01 (16.98%). The most common class II alleles were
DPA1*01:03:01 (40.60%), DPB1 * 01:01:01 (23.45%), DQA1 * 01:02:01 (31.03%),
DQB1 * 03:01:01 (21.79%), DRB1 * 11:01:02 (11.65%), DRB3 * 02:02:01 (31.65%),
DRB4 * 01:01:01 (10.50%), and DRB5 * 01:01:01 (10.50%). Higher than expected
homozygosity was observed at HLA-B (P = 0.022), DQA1 (P = 0.004), DQB1 (P = 0.023),
and DRB1 (P = 0.0006) loci. The allele frequency distribution of this
population is very similar to the ones observed in other sub-Saharan
populations with the exception of lower frequencies of A * 23 (5.55% versus
11.21%) and DQA1 * 03 (4.79% versus 11.72%), and higher frequencies of DPB1 *
30 (2.26% versus 0.37%) and DRB1 * 11 (21.51% versus 15.89%). The knowledge of
the diversity and allele/ phenotype frequencies of the HLA alleles of this east
African population, can contribute to the understanding of how host genetic
factors influence disease susceptibility and effective anti-retroviral
treatment of HIV infections and future vaccine trials.