While selective serotonin reuptake blockers are among the most widely prescribed medications
in the world, many patients do not respond. Specifically, the largest clinical effectiveness study of citalopram reported that less than 30% of the entire sample of patients experienced a complete remission of their symptoms.11 While the ultimate Inhibitors,research,lifescience,medical goal of pharmacodynamically designed pharmacogenomic testing is to identify a drug for a specific patient that will definitely be effective, at the current stage of our understanding, it is only possible to identify a medication that is more likely to be effective. The serotonin transporter gene (SLC6A4) SLC6A4 is located on chromosome 17 and consists of 37 800 nucleotides. It codes for an enzyme that is composed of 630 amino acids. SLC6A4 is the most widely genotyped pharmacogenomic “target” gene. A meta-analysis of studies Inhibitors,research,lifescience,medical of the relationship between the more active long form of the indel promoter variant of this gene and responses to selective serotonin
reuptake inhibitors12 confirmed the early finding that the Inhibitors,research,lifescience,medical long form is associated with a more rapid and better response.13 However, this has not consistently been demonstrated Inhibitors,research,lifescience,medical in patients of Asian ancestry.14, 15 The importance of ancestral heritage has been further demonstrated by multiple analyses of the large STAR*D effective treatment study. Analyses that did not consider ancestral background did not demonstrate a selleck bio significant association,16 while those that focused on patients who identified themselves as “white”
but not “Hispanic” did confirm the relationship that patients who were homozygous for the more Inhibitors,research,lifescience,medical active long form of the indel promoter polymorphism were more likely to respond to citalopram. Other variants, such as rs2553117 and the Idelalisib CLL second intronic VNTR18 are likely to influence the activity level of the gene and, consequently, its response to medications Dacomitinib that block its ability to reuptake serotonin in the synapses of the central nervous system. The serotonin receptor 2A gene (HTR2A) HTR2A is located on chromosome 13 and consists of 62 663 nucleotides. Despite its large size, it codes for an enzyme that is composed of only 471 amino acids. There have been a series of studies examining the association between variants of HTR2A and antidepressant response. A large study examining the response of depressed patients of European ancestry to citalopram found that a positive response to citalopram was associated with having a copy of the adenine allele of rs7997012.