IFNG and Mendelian susceptibility to mycobacterial diseases: An alternative may be the use of functional screening assays for MSMD, like the ones implemented in this study, which can identify immune deficits in the IL-12-IFN-γ pathways and inform whether targeted Sanger sequencing can be used to find a molecular diagnosis based on their functional readout, or whether the patient should be referred for further investigation through NGS.