Association of HLA-DRB1 Alleles with Rheumatic Fever Among Senegalese Patients

Abstract

Background: Acute rheumatic fever (ARF) is a systemic inflammatory disease resulting from an abnormal immune response to group A β-hemolytic streptococci. ARF is a major public health problem in developing countries, particularly in Senegal. The aim of this study was to evaluate the mutation penetrance and genetic diversity of exon 2 of the HLA-DRB1 gene in Senegalese patients with ARF. Results: DNA was extracted from the blood of patients with ARF. Exon 2 of the HLA-DRB1 gene was amplified by polymerase chain reaction and sequenced using the Sanger method. Bioinformatics software and databases (polyphen-2, SIFT and ProVean) were used to assess the pathogenicity of missense mutations. The results revealed a high level of polymorphism in exon 2 of the HLA-DRB1 gene, with 73 non-synonymous mutations between codons 21 and 89, which lie in the hypervariable region encoded by exon 2. Of the 73 variants tested, 44% were pathogenic, indicating their potential involvement in ARF onset. Conclusion: Our results indicate that the HLA-DRB1 mutations involvement in the onset of rheumatic fever.