Pharmacogenetics is the study of genetic variations that cause a variable drug response characterized by alteration in drug metabolism or in pharmacodynamics. The polymorphisms in genes encoding receptors relevant to treatment cause variation in sensitivity to many drugs. β2 Adrenoceptor genetic variation contributes to regulation of blood pressure and hemodynamic changes by mediating peripheral vasodilatation. Laryngoscopy and tracheal intubation associated with hemodynamic changes. Although there are four nonsynomic single-nucleotide polymorphisms (SNPs) of β2 adrenoceptor gene, codon 16 (Arg16Gly) and codon 27 (Gln27Glu) SNPs are both common and functionally important. In this paper, the authors investigated the β2 adrenoceptor Gly16 and Glu27 SNPs in response to drugs relevant to anesthesia and how these SNPs impacted upon the cardiovascular phenotypes. The authors measured arterial systolic and diastolic blood pressure, heart rate, and rate-pressure product before induction of anesthesia and 1 min following laryngoscopy and tracheal intubation. Genomic DNA was amplified and genotyped using allele-specific polymerase chain reaction (ASPCR) and restriction fragment length polymorphism (RFLP) assays, respectively. When the authors compared hemodynamic results according to genotypes, the patients with Gln homozygote allele at codon 27 exhibited significant increase of heart rate than patients with Glu allele after laryngoscope and tracheal intubation. Copyright © American College of Toxicology.