Methods

The allele frequency table was made by searching the PubMed® database (1995 to 2021).

Caveats to estimated allele frequencies:

Sampling. Allele frequencies collected by CPIC for the supplemental tables are based on published literature reports which typically study small groups of people based on a geographic location (e.g. Malaysia, Berlin, Cairo). Almost no studies use genetic markers to estimate ancestry. Manuscripts are often focused on a specific phenotype (e.g. disease) or study only individuals taking a particular drug. Such samples would not be considered a random sample of the general population. Another consideration is that sample size is important, and PGx studies are typically not large. The frequencies collected from these studies are then used to estimate general estimates of entire ethnic population allele frequencies. Therefore, frequencies from larger groups of subjects and frequencies averaged from many sample populations probably result in better estimates.

Biogeographical groups. Biogeographical groups are derived from PMID 30506572. Further details can be found at https://www.pharmgkb.org/page/biogeographicalGroups. These tables group individuals from particular geographic locations into larger biogeographical groups. It is difficult to group populations with certainty, because some populations are often admixed, or at the least, a combination of different ethnicities. Therefore, the margin of error is increased when different subpopulations are grouped together.