Mendelian Susceptibility to Mycobacterial Diseases (MSMD) in a 13-Year-Old Ethiopian Girl with Autosomal Dominant Interferon Gamma Receptor 1(IFN-<i>γ</i> R1) Defect: A Clinical Diagnostic and Treatment Challenge. The gene discussed is IFNGR1; the disease is Mendelian susceptibility to mycobacterial diseases.