HTR2A Genotyping

HTR2A is a post-synaptic serotonin receptor that binds serotonin and is involved in amplification of excitatory signals to other neurons in the brain. HTR2A is located in many brain regions. The involvement of HTR2A in antidepressant and antipsychotic effectiveness and risk of side effects is not fully understood, however blocking the HTR2A receptor may improve antidepressant effectiveness and mitigate the extrapyramidal symptoms of antipsychotics. Some polymorphisms of this gene may decrease receptor density and activity in some areas of the brain, which may affect antidepressant and antipsychotic response and risk of adverse effects.


Indications for Testing

Individuals initiating an antidepressant or antipsychotic or with a history of adverse drug effects or reactions to SSRIs may be good candidates for HTR2A testing. Testing for HTR2A polymorphisms can help predict which patients may be more likely to experience SSRI-induced adverse effects and provide supplemental information to determine if patients will adequately respond to therapy. Decisions to modify therapy should not be based solely on HTR2A polymorphisms as multiple factors in addition to the HTR2A polymorphism likely contribute to antidepressant and antipsychotic response.


Insurance Coverage

HTR2A testing is currently not covered by Medicare. Private insurance coverage varies by insurance company. The CPT code for HTR2A testing is 81479 (provided as guidance only).


Specimen Collection

Click here to order testing supplies or call Client Services at 800-837–8362.

  • Buccal Swabs: 4 sterile buccal swabs
  • Blood: 5-10cc whole blood lavender-top EDTA or yellow-top ACD-A tubes

Turnaround Time: 7 business days, faster turnaround available for clinical trials