ATP7B

The ATP7B gene provides instructions for making a protein that is important for copper transport and the elimination of excess copper from the body. This protein is found primarily in the liver, with smaller amounts in the kidneys and brain. The ATP7B protein is part of the P-type ATPase family, a group of proteins that transport metals into and out of cells using the energy molecule adenosine triphosphate or ATP.

Within liver cells, the ATP7B protein is found in a structure called the Golgi apparatus, which modifies newly produced enzymes and other proteins. Here, the ATP7B protein supplies copper to another protein (ceruloplasmin) that transports copper in the blood to other parts of the body. If copper levels in the cell get too high, the ATP7B protein leaves the Golgi and transfers copper to vesicles for elimination.

Wilson disease - caused by mutations in the ATP7B gene

Researchers have identified more than 200 ATP7B mutations that can cause Wilson disease. About half of the mutations cause an incorrect replacement of a single amino acid (the building material of proteins) in the ATP7B protein. These mutations alter the three-dimensional structure of the protein or its stability, preventing the proper functioning of the ATP7B protein. The most common substitution replaces histidine with glutamine at position 1069 in the protein's chain of amino acids (also written as His1069Gln). This particular mutation occurs in about 40 percent of affected individuals with a Northern or Eastern European ancestry. Approximately one-third of Asian people with Wilson disease have a mutation that replaces arginine with leucine at position 778 (also written as Arg778Leu). In the Costa Rican population, more than 60 percent of affected individuals have a mutation that replaces aspartic acid with serine at position 1270 (also written as Asp1270Ser).

Other types of mutations delete or insert small segments of DNA within the ATP7B gene or introduce a stop signal that halts production of the protein prematurely. As a result, little or no functional ATP7B protein is made. With a shortage of functional protein, excess copper is not removed from the body and can accumulate to toxic levels in the liver, brain, and other tissues.

13q14.2-q21

The ATP7B gene is located on the long (q) arm of chromosome 13 between positions 14.2 and 21.

See How do geneticists indicate the location of a gene? in the Handbook.

You and your healthcare professional may find the following resources about ATP7B helpful.

• Gene Reviews - Clinical summary
• Gene Tests - DNA tests ordered by healthcare professionals

You may also be interested in these resources, which are designed for genetics professionals and researchers.

• PubMed - Recent literature
• OMIM - Genetic disorder catalog
• Research Resources - Tools for researchers (5 links)

See How are genetic conditions and genes named? in the Handbook.

The Handbook provides basic information about genetics in clear language.

• What is DNA?
• What is a gene?
• How does a gene make a protein?
• How can gene mutations cause disorders?

These links provide additional genetics resources that may be useful.

• Genetics education
• Human Genome Project
• Resources for Genetic Researchers

adenosine triphosphate ; amino acid ; ATP ; ceruloplasmin ; DNA ; enzyme ; gene ; Golgi apparatus ; molecule ; mutation ; polypeptides ; protein ; serine ; substitution

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.