CYP2D6

Role in the organism:

Most of the drugs we use are broken down by a group of enzymes, known as the cytochrome P450 family, that function in the liver. CYP2D6 is responsible for the breakdown of more than 30 classes of compounds. For example, the antidepressant amitriptyline and the beta-blocker 4-hydroxylase-debrizoquin.

Role in the disorder (state):

High levels of CYP2D6 gene expression are associated with several forms of cancer, reflecting the fact that some of the metabolic products resulting from the breakdown of drugs and other chemicals are carcinogens. All CYP enzymes are highly polymorphic and over 70 variants of CYP2D6 genes have been documented. This plays an important role in determining our response to medication. About 20 variants of the CYP2D6 gene are non-functional. Individuals with two copies of these alleles have poor drug metabolism - drugs break down very slowly. Individuals who have normal functional alleles normally carry out drug metabolism. Multiple copy individuals have rapid drug metabolism. Doses of medication for different types of metabolism must be carefully controlled to prevent overdose.