Note from the Editor-in-Chief

The Virtual Journal in Pharmacogenetics-Pharmacogenomics represents a guided tour of the literature, using PubMed and selected MESH words for comprehensive coverage (https://www.aapspharmsci.org/theme_issues/virtual/). We will occasionally publish Commentaries on recent articles of general interest. In the present Commentary, Schubbert analyzes two discordant papers by Drysdale et al, and Martinez et al. that describe associations between β2 receptor genotype and response to albuterol. The significance of this comparison lies in the use of haplotypes (multiple phased SNPs on the same chromosome) and isolated SNPs, respectively. The two studies lead to opposite conclusions with respect to a polymorphism (R16G) with well described functional effects on β2 receptor regulation. The use of haplotypes has recently gained much attention as a discriminating tool in linking genotype to phenotype. Advantages include the fact that haplotypes may reflect the interaction among several functionally significant polymorphisms on the same chromosome, and they can define additional sub-populations in the treatment groups. However, haplotypes may have vastly different distributions among different ethnic populations, and therefore, can introduce bias that could obscure a true relationship of a single functional SNP. The Commentary sheds light on possible factors that could resolve the discrepancies in the two studies.

W.Sadée, Editor-in-Chief, AAPS PharmSci