A comparison of methods for determining genotypes at the tumour necrosis factor-alpha-308, interleukin...

Induced heteroduplex genotyping (IHG) is one of many methods that can be used to determine single nucleotide polymorphisms (SNPs). It is relatively new in comparison to other polymerase chain reaction (PCR)-based techniques. The aim of this study was to compare the results of genotyping using IHG with the results of genotyping using either polymerase chain reaction-sequence-specific primers (PCR-SSP) or polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for SNPs in the tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6 and IL-10 genes. Ninety patients who consented to participate in the study had their genotypes determined by IHG and either PCR-SSP (TNF-alpha-308 and IL-10 -1082/-819/-592) or PCR-RFLP (IL-1beta +3953 and IL-6 -174). Results for each locus were compared between techniques by calculating the Kappa statistic as a measure of agreement. The IHG and more traditional genotyping methods produced very similar results at all loci. The Kappa statistics for each locus were as follows: TNF-alpha -308, K = 0.727; IL-1beta +3953, K = 0.886; IL-6 -174, K = 0.909; IL-10 -1082, K = 0.876; IL-10 -592, K = 0.920. IHG is a valid method for the determination of genotypes at the loci examined in this study and produces comparable results to those of more traditional methods of genotyping.