Understanding the relationship between a genotype and phenotype can be extremely useful in a variety of research areas.
A particularly interesting area is pharmacogenomics. Genetic variations can occur in liver enzymes required for drug metabolism, such as CYP450. Therefore, an individual’s phenotype, i.e. their ability to metabolize a specific drug, may vary depending on which form of the enzyme-encoding gene they possess. For pharmaceutical companies and physicians, this knowledge is key for determining recommended drug dosages across populations.
Making use of genotyping and phenotyping techniques in tandem appear to be better than using genotype tests alone. In a comparative clinical pharmacogenomics study, a multiplexing approach identified greater differences in drug metabolism capacity than was predicted by genotyping alone. This has important implications for personalized medicine and highlights the need to be cautious when exclusively relying on genotyping.