Interethnic diversity of the CD209 (rs4804803) gene promoter polymorphisms in African but not American sickle cell disease

• Published in: PeerJ preprints 2014-11
• Main Authors: Noble, Jenelle A, Duru, Kimberley C, Guindo, Aldiouma, Li, Yi, Diallo, Dapa A, Bolaji, Thomas
• Format: Article
• Language: English
• Subjects: African Americans; Gene polymorphism; Immune response; Infectious diseases; Polymerase chain reaction; Restriction fragment length polymorphism; Sickle cell disease; Single-nucleotide polymorphism
• ISSN: 2167-9843
• DOI: 10.7287/peerj.preprints.597v1

Elucidating the genomic diversity of CD209 gene promoter polymorphisms could assist in clarifying disease pathophysiology as well as contribution to co-morbidities. CD209 gene promoter polymorphisms have been shown to be associated with susceptibility to infection. We hypothesize that CD209 mutant variants occur at a higher frequency among Africans and in sickle cell disease. We analyzed the frequency of the CD209 gene (rs4804803) in healthy control and sickle cell disease (SCD) populations and determined association with disease. We obtained genomic DNA from 145 SCD and 244 control Africans (from Mali), 331 SCD and 379 control African Americans and 159 Caucasians. Comparative analysis among and between groups was carried out by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Per ethnic diversification, we found significant disparity in genotypic (23.4% versus 16.9% versus 3.2%) and allelic frequencies (36.1% versus 25.1% versus 11.6%) of the mutant variant of the CD209 (snp 309A/G) gene promoter between Africans, African Americans and Caucasians respectively. Surprisingly, there was a wide disparity in the genotypic and allelic frequencies among African SCD versus healthy controls (10.4% versus 23.4% (genotypes) and 25.2% versus 36.1% (alleles), which is completely absent among African Americans. Comparing SCD groups, there was no difference between Africans and Americans, implying a lack of association between CD209 polymorphisms and sickle cell disease in either population. The higher frequency of CD209 mutant variants in the non-SCD group reveals an impaired capacity to mount an immune response to infectious diseases. We conclude that CD209 polymorphism play a major role in susceptibility to infectious pathogens and could potentially delineate susceptibility to and severity of co-morbidities.