Prevalence and Influence of the -174 G/C Polymorphism in the Interleukin-6 Gene in Arboviruses Infections.

Dengue virus and Chikungunya virus are arboviruses that affect thousands of people worldwide annually. The mechanisms involved in viral pathogenesis still need to be better understood. Single nucleotide polymorphisms (SNPs) in immune genes may be involved in the protection, susceptibility, and/or progression of these diseases. This study was performed to investigate the SNP -174 G/C in the interleukin-6 (IL-6) gene in patients with dengue or chikungunya from Northeastern Brazil. A total of 581 blood samples were analyzed, of which 244 were part of the negative control group, genomic DNA was extracted, and the SNP was genotyped using real-time polymerase chain reaction (PCR). The data obtained were used to conduct statistical analyses of the genotype and allele frequencies. We suggest that the G/C genotype and C allele of the SNP -174 G/C in the IL-6 gene are related to protection against dengue in the studied population. No significant differences were observed in chikungunya patients. This is the first study that assessed the association of the SNP -174 G/C in patients with chikungunya. We identified the presence of the C allele as a protective factor against dengue in the studied population.

Brugada syndrome in a family with a high mortality rate: a case report.

INTRODUCTION: Brugada syndrome is a hereditary arrhythmia characterized by a specific electrocardiographic pattern and an increased risk of sudden cardiac death, with an apparent absence of structural abnormalities or ischemic heart disease. To date, mutations in the sodium channel, voltage-gated, type V, alpha subunit gene and glycerol-3-phosphate dehydrogenase 1-like gene are estimated to account for approximately 28% of Brugada syndrome probands. CASE PRESENTATION: We report the case of a 32-year-old mixed-race Brazilian man who is sodium channel, voltage-gated, type V, alpha subunit gene and glycerol-3-phosphate dehydrogenase 1-like gene mutation-negative with a type 1 Brugada electrocardiographic pattern and a history of high family mortality, including five sudden deaths among relatives of whom four were first-degree relatives. CONCLUSION: To the best of our knowledge, this is the first case of a patient who has Brugada syndrome and a history of sudden death in four first-degree family members. This case report reinforces the evidence that genetic studies are of limited use while determining risk but remain helpful for diagnosis, and that diagnosis via electrocardiography is of great importance in preventing adverse events and stratifying risk. Although there are several technologically advanced diagnostic tools, they might not be accessible in small towns and hospitals; however, a basic diagnostic tool like electrocardiography is easily accessible.