Gain-of-function mutation

Gain-of-function mutation is a type of mutation that results in a new or enhanced function of a gene. This type of mutation can lead to the production of a protein with a new function or to increased production of a protein. Gain-of-function mutations are often associated with diseases, including cancer and neurological disorders.

Overview

A gain-of-function mutation occurs when the change in the gene's sequence increases the protein's activity level, promotes a new activity, or leads the protein to appear in inappropriate cells or tissues. In contrast to loss-of-function mutations, which result in a gene product with less or no function, gain-of-function mutations can have a variety of effects on the organism, depending on the specific nature of the mutation.

Mechanisms

Gain-of-function mutations can occur through several mechanisms. One common mechanism is through a change in the gene's sequence that results in an increase in the activity level of the protein. This can occur through changes in the gene's promoter region, leading to increased transcription of the gene, or through changes in the coding region of the gene, leading to a protein that is more active or stable.

Another mechanism is through a change in the gene's sequence that results in the protein appearing in cells or tissues where it is not normally found. This can lead to a variety of effects, depending on the function of the protein and the cells or tissues where it is expressed.

Diseases associated with gain-of-function mutations

Gain-of-function mutations are associated with a variety of diseases. For example, they are often found in cancer cells, where they can lead to uncontrolled cell growth and division. In neurological disorders, gain-of-function mutations can lead to the production of proteins that are toxic to nerve cells.

Some specific examples of diseases associated with gain-of-function mutations include:

• Huntington's disease: This is caused by a gain-of-function mutation in the HTT gene, which leads to the production of a toxic protein that damages nerve cells.
• Marfan syndrome: This is caused by a gain-of-function mutation in the FBN1 gene, which leads to the production of a protein that affects connective tissue.
• Neurofibromatosis: This is caused by a gain-of-function mutation in the NF1 gene, which leads to the production of a protein that promotes cell growth.

See also

• Mutation
• Loss-of-function mutation
• Genetic disease