Cytochrome P450 Polymorphisms

Abstract

The human genome comprises 57 putatively functional, protein‐coding cytochrome P450 (CYP) genes that are grouped according to their sequence similarity into 18 families and 44 subfamilies. Approximately one dozen CYP isozymes of families 1, 2, and 3 are mainly responsible for the metabolism of drugs and other xenobiotics. Large interindividual variability of these enzymes, to which both genetic and nongenetic factors contribute, is an important determinant of drug pharmacokinetics and drug response. This chapter summarizes the functional, clinical, and toxicological relevance of human P450 genetic polymorphism, which affects all drug‐metabolizing CYPs, but to a very different extent.

Frequency of genetic polymorphism for adrenergic receptor beta and cytochrome p450 2D6 enzyme and effects on the tolerability to Beta-blocker therapy in heart failure with reduced ejection fraction patients: Beta GenTURK Study

“…Patients are commonly classified as ultra extensive metabolizers, extensive metabolizers, intermediate metabolizers, or poor metabolizers, based on their number of copies of functional CYP2D6 allele. [41] The Cyp2D6*10 allele is one of the most important Cyp2D6 variants with reduced enzymatic activity, which are referred to as residual functional alleles. As individuals with homozygous mutant genotypes of this allele are usually intermediate or poor metabolizers, it has been suggested that they will be more sensitive to BBs.…”