Mendelian Susceptibility to Mycobacterial Disease: The FirstCase of a Diagnosed Adult Patient in the Czech Republic

We present a case of a 42-year-old woman with Mendelian susceptibility to mycobacterial disease. )e disease was diagnosed at anadult age with relatively typical clinical manifestations; the skeleton, joints, and soft tissues were affected by nontuberculousmycobacteria:Mycobacterium lentiflavum,M. kansasii, andM. avium. A previously published loss-of-function and functionallyvalidated variant NM_000416.2:c.819_822delTAAT inIFNGR1in a heterozygous state was detected using whole-exome se-quencing. After interferon-ctherapy was started at a dose of 200μg/m2three times a week, there was significant clinical im-provement, with the need to continue the macrolide-based combination regimen. In the last 4 months, she has been in this therapywithout the need for antibiotic treatment.