REEP5 rs153549: Antidepressant Response Genetic Variant
The rs153549 single nucleotide polymorphism is an intronic genetic variant located within the REEP5 gene on chromosome 5. Preliminary pharmacogenomic investigations have explored whether variations at this locus correlate with treatment outcomes in patients prescribed selective serotonin reuptake inhibitors (SSRIs) for major depressive disorder. However, current clinical evidence remains limited and observational, meaning it does not alter standard medical prescribing guidelines.
What each genotype means
| Genotype | What the research suggests | Reading |
|---|---|---|
| TT | Carriers of two copies of the T allele have been analyzed in psychiatric pharmacogenomic studies investigating SSRI efficacy. In candidate research cohorts, this genotype has served as a reference profile with average, population-typical antidepressant response patterns. The finding represents statistical population data and does not guarantee medical treatment outcomes. | Informational |
| CT | Individuals who carry one C allele and one T allele possess a heterozygous genotype commonly found across diverse global ancestral groups. Preliminary candidate studies have noted exploratory statistical differences in antidepressant outcomes among heterozygous individuals compared to homozygotes. Because broader scientific evidence remains mixed, this genotype should not be interpreted as a diagnostic or clinical prediction. | Informational |
| CC | Carriers of two copies of the C allele display an alternative homozygous profile evaluated in exploratory depression pharmacogenetics studies. Certain observational reports have scrutinized whether homozygous C carriers experience altered rates of symptom remission on specific SSRIs, but evidence remains preliminary and unvalidated by formal guidelines. This genotype does not justify changes to clinical medication choices or dosing. | Higher attention |
Genomic Location and Characteristics of rs153549
The single nucleotide polymorphism (SNP) designated rs153549 is positioned within an intronic region of the REEP5 gene on the long arm of human chromosome 5. Because it resides inside non-coding sequence rather than an exon, it does not directly alter the amino acid sequence of the encoded protein. Variants in intronic loci often function by subtly modulating transcription rates, alternative splicing patterns, or transcript stability, though they may also simply act as neutral genetic markers inherited in high linkage disequilibrium alongside nearby causative variants. Cataloged across broad genomic resources such as dbSNP and Ensembl, rs153549 represents a standard bi-allelic base substitution typically involving thymine (T) and cytosine (C) alleles. Understanding its precise molecular positioning provides researchers with a structural roadmap for analyzing how non-coding genomic variation within chromosomal region 5q22 might correlate with systemic drug response variability.
Biological Role of the REEP5 Gene
The REEP5 gene encodes receptor accessory protein 5, a conserved integral membrane protein belonging to the DP1/REEP protein family. REEP5 localizes primarily to the tubular endoplasmic reticulum (ER) and sarcoplasmic reticulum membranes, where it plays a fundamental structural role in stabilizing ER curvature and maintaining high-membrane curvature networks. Beyond shaping cellular architecture, REEP proteins assist in intracellular vesicle trafficking and can interact with or modulate the surface expression of particular cell-surface receptors. REEP5 is expressed across a wide range of human tissues, with notable levels detected in both peripheral organs and the central nervous system. Because cellular stress response, neuroplasticity, and receptor trafficking within neural circuits are increasingly recognized as downstream pathways relevant to mood regulation and psychotropic drug action, researchers have hypothesized that variations in ER-shaping proteins like REEP5 could plausibly influence how neural cells adapt to prolonged pharmacological stimulation.
Current Research on Antidepressant Treatment Response
Pharmacogenomic candidate-gene and exploratory association studies have evaluated rs153549 in cohorts of individuals diagnosed with major depressive disorder (MDD) undergoing treatment with selective serotonin reuptake inhibitors, including fluoxetine, citalopram, paroxetine, and sertraline. Some initial published cohorts, including studies evaluating Asian populations, reported statistically significant differences in genotype frequencies between individuals achieving clinical response or remission and those with treatment-resistant symptoms. However, across the broader psychiatric genetics landscape, genome-wide association studies (GWAS) and systematic pharmacogenomic reviews note that the evidence for rs153549 remains limited. Associations uncovered in smaller candidate studies have not achieved uniform replication across diverse ancestral cohorts, nor has rs153549 been elevated to a definitive pharmacogenomic biomarker with high effect sizes. At present, PharmGKB catalogs this finding as lower-level, preliminary clinical research rather than a validated predictor.
Clinical Guidelines and Actionability
Unlike well-established pharmacogenes such as CYP2D6 and CYP2C19—which have formal, actionable clinical guidelines issued by the Clinical Pharmacogenetics Implementation Consortium (CPIC) and the Dutch Pharmacogenetics Working Group (DPWG)—the REEP5 rs153549 variant possesses no regulatory endorsements or dosage recommendations. Major global health authorities, including the U.S. FDA, do not endorse modifying antidepressant therapy based on an individual's rs153549 genotype. Antidepressant response is a complex, multifactorial clinical outcome governed by dozens of subtle genetic loci, drug pharmacokinetics, age, baseline symptom severity, concurrent medications, and psychological factors. Consequently, an individual genotype at this single locus cannot predict whether an antidepressant will be effective or cause adverse side effects. Patients must never alter, initiate, or discontinue antidepressant regimens based on personal genomic data without direct guidance from their treating physician or psychiatric clinical pharmacist.
How common is this variant?
The rs153549 variant is a common single nucleotide polymorphism observed at substantial frequencies across diverse global populations in large reference databases such as gnomAD and the 1000 Genomes Project.
Frequently asked questions
Can testing my rs153549 genotype tell me which antidepressant to take?
No, commercial DNA testing of rs153549 cannot determine which antidepressant will work for you. Scientific findings linking REEP5 to medication response are preliminary, and major regulatory agencies and clinical consortiums like CPIC do not recommend selecting or avoiding medications based on this variant.
Does having a specific rs153549 genotype mean I have major depression?
No, rs153549 is not a diagnostic test for major depressive disorder or any other mental health condition. It is a common non-coding variant evaluated strictly in pharmacogenomic research for its possible statistical correlation with treatment response in people already diagnosed with depression.
Why do some pharmacogenomic reports mention the REEP5 gene?
Some exploratory research panels include REEP5 because early candidate gene studies suggested its intronic variants might correlate with response to certain selective serotonin reuptake inhibitors (SSRIs). However, because these early associations lack broad replication across large clinical trials, they remain experimental.
What should I do if my genetic data shows a REEP5 variant?
You should not make any changes to your prescription medications or mental health treatment based on your genetic results. Always share your complete genetic testing report with your prescribing physician or pharmacist to discuss evidence-based medication planning.
Sources & further reading
Educational information only, last refreshed 9/7/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs153549?
Upload a raw DNA file from 23andMe, AncestryDNA, MyHeritage, or FamilyTreeDNA and see this variant — plus thousands more — interpreted in your full report.
Get my report — $29