The Human Cytochrome P450 (CYP) Allele Nomenclature website: a peer-reviewed database of CYP variants and their associated effects

Hum Genomics. 2010 Apr;4(4):278-81. doi: 10.1186/1479-7364-4-4-278.


Pharmacogenetics affects both pharmacokinetics and pharmacodynamics, thereby influencing an individual's response to drugs, both in terms of response and adverse reactions. Within the area of pharmacogenetics, findings of genetic variation influencing drug levels have been more prevalent, and variation in the cytochrome P450 (CYP) enzymes is one of the most common causes. Much of the work concerning sequence variations in CYPs aims at finding biomarkers of use for individualised treatment, thereby increasing the treatment response, lowering the number of side effects and decreasing the overall cost of treatment regimens. For over ten years, the Human Cytochrome P450 Allele Nomenclature (CYP-allele) website ( has offered a database of genetic information on CYP variants, along with effects at the molecular as well as clinical level. Thus, this database serves as an assembly of past, current and soon-to-be published information on CYP alleles and their outcome effects. The website is used by academic researchers and companies (eg as a tool in drug development and for outlining new research projects). By providing peer-reviewed genetic information on CYP enzymes, the CYP-allele website has become increasingly popular and widely used. Recently, NADPH cytochrome P450 oxidoreductase (POR), the electron donor for CYP enzymes, was included on the website, which already contains 29 CYP genes, hence POR alleles are now also designated using the star allele (POR*) nomenclature. Although most CYPs on the CYP-allele website are involved in the metabolism of xenobiotics, polymorphic enzymes with endogenous functions are also included. Each gene on the CYP-allele website has its own webpage that lists the different alleles with their nucleotide changes, their functional consequences and links to publications in which the allele has been identified and/or characterised. Thus, the CYP-allele website offers a rapid online publication of new alleles, as well as providing an overview of peer-reviewed data.

MeSH terms

  • Alleles*
  • Cytochrome P-450 Enzyme System / classification*
  • Cytochrome P-450 Enzyme System / genetics*
  • Cytochrome P-450 Enzyme System / metabolism
  • Databases, Genetic*
  • Genetic Variation*
  • Humans
  • Internet
  • Peer Review
  • Terminology as Topic
  • Xenobiotics


  • Xenobiotics
  • Cytochrome P-450 Enzyme System