COX6A2

COX6A2 is a gene that encodes a subunit of cytochrome c oxidase (COX), the last enzyme in the mitochondrial electron transport chain which drives oxidative phosphorylation. The encoded protein is a member of the cytochrome c oxidase VIa family. Defects in this gene are a cause of severe infantile encephalomyopathy.

Function[edit | edit source]

The COX6A2 gene provides instructions for making a protein that is a subunit of the cytochrome c oxidase complex, also known as complex IV. This complex is the last of four complexes in the mitochondrial respiratory chain, which is part of a process called oxidative phosphorylation. The cytochrome c oxidase complex helps transfer electrons from cytochrome c, a carrier protein, to oxygen, the final acceptor of electrons in the respiratory chain. This transfer helps drive the production of adenosine triphosphate (ATP), the cell's main source of energy.

Clinical significance[edit | edit source]

Mutations in the COX6A2 gene have been associated with severe infantile encephalomyopathy, a condition characterized by a lack of energy (lethargy), weak muscle tone (hypotonia), and delayed development. These mutations reduce the activity of the cytochrome c oxidase complex, impairing oxidative phosphorylation and leading to a shortage of ATP in cells. This shortage can disrupt the function of many types of cells, including those in the brain and muscles, leading to the signs and symptoms of severe infantile encephalomyopathy.