Why it is crucial to conduct pharmacogenenetic studies across different racial groups?

In this assignment, you will use capecitabine and DPYD to compare between three resources for pharmacogenetics information: CPIC, DWPG, FDA pharmacogenomic association table.
In a table, 1. Provide the actionable genotype(s)/phenotype(s) and the rationale behind the actionability in each resource, if stated.
I am providing an example of CYP2C19 and drug A
For example, assuming that CYP2C19 influences the metabolism of drug (A) into inactive drug. Then CYP2C19 *1/*2 (intermediate metabolizer, IM), CYP2C19 *2/*2 (poor metabolizers, PM) will be at risk of developing high plasma levels of drug (A). Therefore, patients with intermediate and poor metabolizer phenotypes are at high risk for developing adverse events from Drug A. Your answer should include
The actionable genotypes/phenotypes for Drug A: are CYP2C19 genotypes *1/*2 (IM), *2/*2 (PM).
Rationale: Since CYP2C19 influences the drug metabolism of drug A, individuals with intermediate and poor metabolizer phenotypes are likely to have high drug levels compared to these individuals with normal metabolizer phenotype, thus, these patients are at risk of developing side effects from drug A
Comparison of the therapeutic recommendations will include stating the dosing recommendations, if any, across the three resources.
Comparing the evidence of recommendation (Strong, Moderate, Low), if stated. This will be stated in CPIC and DPWG but not in the FDA table.
Part 2
Answer the following two questions (10 points)
1. You are conducting a pharmacogenetics association analysis that aims to identify a variant associated with a drug-induced skin reaction. The study identified a variant A that is associated with a cutaneous reaction. Patients who are carrier of the A allele are at 4 times higher risk of developing the adverse drug reaction. The genotype frequency of (AA) is 0.16. How many patients would develop an adverse drug reaction if the drug was given to 250 patients? Hint: use HWE equation that states p+q=1.
2. Why it is crucial to conduct pharmacogenenetic studies across different racial groups?