The ultimate goal in measuring CYP450 function or identifying polymorphisms is to predict effective therapeutic doses and responses in patients.
Polymorphisms are identified using molecular techniques (allele-specific PCR, restriction digests, sequencing, hybridization assays, bead-based systems, microarrays, pyrosequencing, et al).
Although most clinical labs do not offer PGx testing, reference labs are beginning to market these tests. For example, one reference laboratory in the Midwest that offers CYP2D6 profiling measures about one dozen of the most common and significant mutation sites on this enzyme. This allows for detection of approximately 98% of the known CYP2D6 polymorphisms. The laboratory then generates a report which will advise the physician on the patient's drug-metabolizing status.
Estimates show that 6-10% of the general population have a complete deficiency of CYP2D6, with the prevalence of mutations varying from <1% to as much as 21% within a given population.