The genotype of an individual is essentially invariable and remains unaffected by the treatment itself.
Molecular biology techniques provide an accurate assessment of the genotype of an individual.
There has been a dramatic increase in the amount of genomic information that is available. This information provides the necessary data for comprehensive studies of individual genes and broad investigation of genome-wide variation.
The ease of accessibility to genotype information through peripheral blood or saliva sampling and advances in molecular techniques has increased the feasibility of DNA collection and genotyping in large-scale clinical trials.