Obstructive sleep apnoea (OSA) is a prevalent breathing disorder that decreases the quality of life, and may lead to severe comorbidities. The complex genetic components of OSA pathogenesis advocates for genetic association studies to understand the underlying mechanisms. The tumor necrosis factor (TNF-α -308G/A promoter polymorphism has been associated with OSA susceptibility in several populations, however this relationship has not been studied in the Swedish population. The aim of this study was to assess the genotype- and allele frequencies of TNF-α -308G/A polymorphism in a Swedish OSA cohort, and look for potential associations with clinical parameters related to OSA.
Genomic DNA samples (n=326) from the Swedish RICCADSA cohort was genotyped with PCR-RFLP. PCR fragments were digested with the restriction enzyme NcoI and analysed in an automated Fragment Analyzer. The results indicated no association between the TNF-α -308G/A polymorphism and OSA susceptibility in this cohort, and no association between genotypes or allele carriage regarding severity, BMI distribution, circulatory TNF-α or comorbidities was found.
The results were potentially obscured by the subjects also having coronary artery disease (CAD), which may involve similar mechanisms as OSA. The cohort did not include samples from a matched healthy Swedish control population, meaning that the results may not reflect the actual relationship between TNF-α -308G/A polymorphism and OSA. In future work, inclusion of genotypes and clinical data from a matched healthy control group are required to investigate the potential relationship between the TNF-α -308G/A polymorphism and OSA in the Swedish population.