Current status of researches in genomic medicine and the guidelines for pharmacogenomics (PGx)

Abstract

Since the whole human genome sequence has become available, the methods to search for genes of diseases or drugs responses (traits) have changed dramatically. The former approach designated as "candidate gene approach" is now dominated by "genome-wide approach". In the former approach, researchers search for the genes based on the functions using biochemistry and molecular biology; however, in the latter approach, the genes are searched for by the genetic and statistical methods. Initially, monogenic diseases were the targets of the researches; however, polygenic diseases and drug responses have become the targets. Parametric linkage analysis was quite useful for identifying responsible genes for monogenic diseases. Genome-wide association study (GWAS) has been introduced for the identification of the genes for polygenic diseases and drug responses. GWAS was first introduced from 2002 to 2004 in Center for Genomic Medicine, RIKEN but has expanded rapidly to other countries including US, Europe and Asian countries from 2005. In Nature Genetics journal, about half of the articles published recently include the data from GWAS studies. Both qualitative and quantitative traits have been analyzed by GWAS. Qualitative traits include diseases and drug responses and quantitative traits include physical measures and clinical laboratory test values. Recent reports about the association between drug responses and genes have clarified many important pharmacogenomic associations. For these data to be analyzed efficiently and used appropriately; however, guidelines for researches and clinical tests concerning pharmacogenomics (PGx) are necessary. "Guideline for pharmacogenomic test" was issued in 2009 and, in addition, an extended guideline covering various fields is now being discussed. © 2011 The Pharmaceutical Society of Japan.