XDR TB in a case of IL12Rβ1 deficiency: a case report of Mendelian Susceptibility to Mycobacterial Disease from India.

Mendelian Susceptibility to Mycobacterial Disease (MSMD) is a relatively new term that describes a spectrum of inherited defects in the IL-12/23 and IFN- γ pathways that result in a selective predisposition to disease caused by poorly pathogenic mycobacteria. In contrast to previous reports of patients infected with environmental mycobacteria and BCG, this manuscript elucidates the clinical course and diagnosis of MSMD in a child harboring extensively drug resistant (XDR) Mycobacterium tuberculosis.