ATP7Bgen

ATP7Bgen is not a standard gene symbol in human genetics. It most likely refers to the ATP7B gene, which encodes a copper-transporting P-type ATPase essential for copper homeostasis in humans.

ATP7B encodes a large membrane protein that contains multiple metal-binding domains and transmembrane segments. It functions as an ATP-driven copper pump, delivering copper into the secretory pathway in hepatocytes and contributing to the incorporation of copper into ceruloplasmin. In liver cells, ATP7B activity supports copper export into bile and supports copper loading of apoceruloplasmin to form holo-ceruloplasmin.

The ATP7B protein primarily localizes to the trans-Golgi network under low copper conditions. When intracellular copper levels rise, ATP7B traffics to vesicles and to the canalicular membrane to increase copper excretion into bile. This trafficking is copper-dependent and helps maintain cellular copper balance.

Mutations in ATP7B cause Wilson disease, an autosomal recessive disorder characterized by copper accumulation in liver, brain, and other tissues. Clinical presentations are diverse, including hepatic dysfunction, neuropsychiatric symptoms, and Kayser-Fleischer rings in the cornea. The mutational spectrum is broad, with many missense, nonsense, splice-site, and frameshift variants; some populations harbor founder mutations.

Diagnosis combines biochemical tests (reduced ceruloplasmin, elevated urinary copper) with genetic testing for ATP7B variants. Treatments aim to reduce copper burden and include copper chelators (such as penicillamine or trientine) and zinc therapy to block copper absorption. In severe cases, liver transplantation may be considered. Early diagnosis and ongoing management improve outcomes, though there is no cure that reverses all disease manifestations.