AHCY

adenosylhomocysteinase

Normal Function

Health Conditions Related to Genetic Changes

Hypermethioninemia

More than 10 variants (also known as mutations) in the AHCY gene have been described in people with hypermethioninemia. Most of these variants substitute one amino acid for another amino acid in the S-adenosylhomocysteine hydrolase enzyme, causing it to process methionine less efficiently. Other variants introduce a premature stop signal in the instructions for making the S-adenosylhomocysteine hydrolase enzyme. As a result, a shortened, nonfunctional enzyme is produced. These changes reduce the activity of the S-adenosylhomocysteine hydrolase enzyme, impairing the breakdown of methionine. As a result, methionine builds up in the body, which is known as hypermethioninemia. In some cases, excess methionine can cause intellectual disability or other neurological problems in affected individuals.

More About This Health Condition

Related Conditions

Hypermethioninemia

Health Conditions Related to Genetic Changes

More than 10 variants (also known as mutations) in the AHCY gene have been described in people with hypermethioninemia. Most of these variants substitute one amino acid for another amino acid in the S-adenosylhomocysteine hydrolase enzyme, causing it to process methionine less efficiently. Other variants introduce a premature stop signal in the instructions for making the S-adenosylhomocysteine hydrolase enzyme. As a result, a shortened, nonfunctional enzyme is produced. These changes reduce the activity of the S-adenosylhomocysteine hydrolase enzyme, impairing the breakdown of methionine. As a result, methionine builds up in the body, which is known as hypermethioninemia. In some cases, excess methionine can cause intellectual disability or other neurological problems in affected individuals.