X-linked mendelian susceptibility to mycobacterial diseases

X-linked (XR) Mendelian susceptibility to mycobacterial diseases (MSMD; see this term) describes a rare group of immunodeficiencies due to specific mutations in the inhibitor of kappa light polypeptide gene enhancer in B-cells, kinase gamma (<i>IKBKG</i>) or the cytochrome b-245, beta polypeptide (<i>CYBB</i>) genes. They are characterized by mycobacterial infections, occuring in males.