CYP3A5*3 Polymorphism and Its Clinical Implications and Pharmacokinetic Role

ABSTRACT

The cytochrome P450 (CYP) 3A subfamily is estimated to participate in the biotransformation of 50% of the currently prescribed drugs. Four members of the CYP3A subfamily have been identified in humans CYP3A4, CYP3A5, CYP3A7, and CYP3A43. Initial data suggested that CYP3A5 accounts for only a small proportion of the total hepatic CYP3A in about 20% of samples, but it was later revealed that CYP3A5 represents more than 50% of the total CYP3A amount in some individuals. Several genetic variants have been described for the CYP3A5 gene, of which the CYP3A5*3 allele (gA6986G), the most common form and leading to the loss of CYP3A5 activity, has been extensively investigated in the aspect of pharmacokinetics and disease risk. This review summarized the molecular characteristics of the CYP3A5 gene, and discusses the association of the CYP3A5*3 polymorphism with disease risks such as cancer and hypertension, along with its role in the pharmacokinetics of CYP3A substrates.