Associations of CCR5Δ32 with COVID-19 in an Iraqi Kurdish Population and Global Allele Frequencies of CCR5Δ32

Abstract

abstract:Chemokine receptor 5 Delta 32 (CCR5Δ32), a 32-nucleotide deletion in the receptor’s gene, is associated with infectious diseases (e.g., protection against HIV-1). Studies have yielded conflicting results regarding this receptor and coronavirus disease 2019 (COVID-19) in various nations. No studies have investigated CCR5 genetic polymorphisms in Kurdish populations. Few studies have been performed in Iraq regarding associations of CCR5 with infectious diseases including COVID-19. This study aims to investigate associations of CCR5Δ32 with COVID-19 in an Iraqi Kurdish population and global allele frequencies of CCR5Δ32 associated with various diseases around the world. Conventional polymerase chain reaction was used to explore CCR5Δ32 based on the polymerase chain reaction product size run on agarose gel electrophoresis. Comparisons of the wild-type (W) and the mutant (Δ32) genotypes were statistically analyzed between the control (n = 114) and patient groups (n = 125). In the control group, 109 individuals (95.6%) carried the wild-type homozygous (W/W) genotype, while five individuals (4.4%) carried the heterozygous (W/Δ32) genotype. In the COVID-19 group, the homozygous (W/W) and heterozygous (W/Δ32) genotypes were 123 (98.4%) and two (1.6%), respectively. No homozygous mutants (Δ32/Δ32) were found in the control and patient groups. The allele frequencies of CCR5Δ32 were 2.2% and 0.8% in the control and patient groups, respectively. However, the data analyzed were not statistically significant. The global allele frequency data show that CCR5Δ32 is controversially associated with several diseases, including COVID-19. This is the first study showing the distribution of the CCR5Δ32 allele in Iraqi Kurds. Associations of this allele with COVID-19 infections were not significant, possibly due to the rarity of this deletion. Moreover, this first report of this allele’s frequency in Iraqi Kurds is a unique and novel contribution to population genetics. However, it might still have a role in COVID-19 infections on a larger scale with samples in other ethnic groups in which this allele is common. The results also indicate that this deletion, in Kurds, is neither as common as in Eurasian populations nor as infrequent as in East Asian populations, but it is similar to African or American global frequency data. This highlights the significance of this allele acting as a protective or risk factor against infections, including COVID-19 and HIV.