CNVs of human genes and their implication in pharmacogenetics.

Pharmacogenetics encompasses genetic variation with importance for drug response and adverse drug reactions with emphasis on drug transporters, drug metabolizing enzymes, and drug receptors. The highest penetrance with respect to drug action is generally observed for variability in genes encoding drug metabolizing enzymes, and gene copy number variations play a very important role in this respect. Alleles containing 0-13 active gene copies have been described, and this variation affects the clinical outcome of treatment for about 20-30% of all drugs. Gene copy number variation has also an influence on nicotine metabolism and detoxification by glutathione transferases and sulfotransferases. In the current overview we provide an update of the situation with emphasis on clinically important examples. Copyright 2009 S. Karger AG, Basel.