Chronic Granulomatous Disease

== Chronic granulomatous disease: X-linked == (CGD; OMIM: 306400)

It is an X-linked primary immunodeficiency caused by a mutation in the CYBB gene (localization Xp21.1), encoding the NOX 2 protein (formerly known as the gp91phox glycoprotein). It is part of the so-called cytochrome b-245 (also b558), a catalytically active part of NADPH-oxidase. NADPH oxidase plays a key role in the respiratory firing of phages as it produces superoxide. If the formation of superoxide is impaired, other reactive oxygen species (hydrogen peroxide, hypochlorous acid, etc.) are not formed, which serve as microbicidal agents of phages and participate in the degradation of absorbed particles. In addition, reactive oxygen species are important for pH regulation in phagolysosomes, so that their deficiency may limit the activation of proteolytic phagosomal enzymes. The NADPH-oxidase defect thus causes a considerable weakening of phagocytes, which have only a limited ability to destroy phagocytosed material.

Decreased immunity is manifested from an early age by purulent infections. Increased sensitivity is especially to catalase-producing microorganisms.

Therapy includes prophylactic administration of cotrimoxazole and itraconazole. In severe cases, bone marrow transplantation is considered.

Chronic granulomatous disease: autosomal recessive Type 1
(CGD cytochrome b-positive 1; OMIM: 233700)

This autosomal recessive inherited form of chronic granulomatous disease is caused by a mutation in the NCF1 gene (localization 7q11.23). The gene product is the p47-phox NADPH oxidase subunit. Respiratory burst of phages does not occur again. The clinical manifestation is similar to that of the more common, X-linked form.

Chronic granulomatous disease: autosomal recessive Type 2
(CGD cytochrome b-positive 2; OMIM: 233710)

Another autosomal recessively inherited variant of chronic granulomatous disease is caused by a mutation in the gene for another subunit of NADPH-oxidase, p67-phox (NCF2 gene, localization 1q25).