The enzyme CYP1A2 (full name: Cytochrome P450 1A2) is involved in the metabolisation of xenobiotics, such as drugs. Around 5% of all drugs are metabolised by the enzyme CYP1A2.
Drugs that can be metabolised by the enzyme CYP1A2 include:
- Antidepressants such as amitriptyline, clomipramine, imipramine and fluvoxamine
- Antipsychotics such as clozapine, olanzapine and haloperidol - Other drugs such as tamoxifen (anti-oestrogen), verapamil, mexiletine (calcium blockers), cimetidine (stomach acid reducer), cyclobenzaprine (muscle relaxant), estradiol (oestrogen), zileuton, theophylline (for asthma), propranolol (beta blocker), naproxen (pain reliever and anti-inflammatory drug), paracetamol (pain reliever and antipyretic) and warfarin (anticoagulant)
As only a small proportion of the activity of CYP1A2 can be explained by genetic variations, there is currently no dosing advice based on the enzyme CYP1A2.
The activity of the enzyme CYP1A2 varies from one individual to another.
As a result, the efficacy of a drug can differ from person to person, as can the risk of potential side effects.
This variation can be explained to a limited extent by genetic variations in the CYP1A2 gene. However, the causes of variations in the activity of the enzyme CYP1A2 are largely unrelated to genetic factors.
Partly for this reason, adapted dosing advice will not readily be issued on the basis of your genotype.
When a genotype is determined variations in the CYP1A2 gene are indicated by two so-called alleles. Each allele has a name consisting of an asterisk (*) and a number. An example of a possible CYP1A2 genotype is CYP1A2*1/*1F.
At iGene we determine the following variants (alleles) of the CYP1A2 gene:
CYP1A*1F, CYP1A*1L, CYP1A*1V, CYP1A*1W, CYP1A2*1C, CYP1A*1K, CYP1A*3, CYP1A*4, CYP1A*6, CYP1A*7 and other (classified as CYP1A*1).