Whole Exome Sequence Analysis for Inborn Errors of IL-12/IFN-γ Axis in Patient with Recurrent Typhoid Fever

Abstract

Background. The IL-12/IFN-γ axis pathways play a vital role in the control of intracellular pathogens such as Salmonella typhi. Objective. The study is aimed at using whole exome sequencing (WES) to screen out genetic defects in IL-12/IFN-γ axis in patients with recurrent typhoid fever. Methods. WES using next-generation sequencing was performed on a single patient diagnosed with recurrent typhoid fever. Following alignment and variant calling, exomes were screened for mutations in 25 genes that are involved in the IL-12/IFN-γ axis pathway. Each variant was assessed by using various bioinformatics mutational analysis tools such as SIFT, Polyphen2, LRT, MutationTaster, and MutationAssessor. Results. Out of 25 possible variations in the IL-12/IFN-γ axis genes, only 2 probable disease-causing mutations were identified. These variations were rare and include mutations in IL23R and ZNFX I. Other pathogenic mutations were found, but they were not considered likely to cause disease based on various mutation predictors. Conclusion. Applying WES to the patient with recurrent typhoid fever detects variants that are not much important as other genes in the IL-12/IFN-γ axis. Results of the current study suggest that a large population sizes would be needed to examine the functional relevance of IL-12/IFN-γ axis genes with recurrent typhoid fever.