A rare immunodeficiency syndrome characterized by a narrow vulnerability to poorly virulent mycobacteria such as bacillus Calmette-Guerin (BCG) vaccines and environmental mycobacteria and defined by severe recurrent infections, either disseminated or localized. The most serious variants develop in early childhood with first infections generally occurring around the age of 3. MSMD can be inherited in an autosomal dominant, autosomal recessive or X-linked manner.

A rare immunodeficiency syndrome characterised by a narrow vulnerability to poorly virulent mycobacteria such as bacillus Calmette-Guerin (BCG) vaccines and environmental mycobacteria and defined by severe recurrent infections, either disseminated or localised. The most serious variants develop in early childhood with first infections generally occurring around the age of 3. MSMD can be inherited in an autosomal dominant, autosomal recessive or X-linked manner.