A genetic variant of Mendelian susceptibility to mycobacterial diseases with characteristics of a complete deficiency in interferon gamma receptor 1(IFN-gammaR1), leading to impaired IFN-gamma immunity and, consequently, to severe and often fatal infections with bacillus Calmette-Guérin and other environmental mycobacteria. Infection is disseminated and can involve soft tissue, bone marrow, lungs, skin, bones and lymph nodes. Manifestations include fever, weight loss, hepatosplenomegaly, lymphadenopathies and lepromatous-like lesions. Caused by complete IFN-gammaR1 deficiency due to mutations in the IFNGR1 gene on chromosome 6q23-q24. Transmission is autosomal recessive.