To date, over 200 disease-associated variants in 17 autosomal (IFNGR1, IFNGR2, IL12B, IL12RB1, IL12RB2, STAT1, TYK2, IRF8, SPPL2A, IL23R, ISG15, JAK1, RORC, ZNFX1, TBX21, IFNG and USP18) and two X-linked (IKBKG and CYBB) genes have been described in patients with MSMD (Bustamante, 2020; Kerner et al., 2020; Tom Le Voye et al., 2021; Martin-Fernandez et al., 2022). The gene discussed is IL12B; the disease is Mendelian susceptibility to mycobacterial diseases.