Center for Human Genetics and Laboratory Diagnostics, Dr. Klein, Dr. Rost and Colleagues

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Cytochrome P450 3A4 (CYP3A4) [T88.7]

OMIM number: 124010 (CYP3A4)

Dipl.-Biol. Birgit Busse

Scientific Background

CYP3A4 is the most extensively expressed isoform of the CYP450 system of the liver and the intestinal tract. The enzyme is involved in the oxidative metabolism of many drugs, endogenous steroids as well as xenobiotics. Interindividual differences in the metabolic capacity, however, can be mainly led back to enzyme induction or inhibition due to co-medication or diet. Some genetic variants of CYP3A4 are associated with an altered enzyme activity; however, among Caucasians, the frequency of most variant CYP3A4 alleles is low. Since the clinical relevance of the genetic variants is not completely clarified yet, the analysis is conducted only after prior consultation.