The HTR2A rs6311 and rs6313 polymorphisms and atypical antipsychotics response in schizophrenia: a scoping review

The HTR2A polymorphisms rs6311 (A-1438G) and rs6313 (T102C) have been thoroughly studied for their impact on atypical antipsychotics (AAPs) responsiveness in schizophrenia. However, the results remain inconsistent owing to the complex genetic and pharmacodynamic interactions. The Joanna Briggs Institute and Preferred Reporting Items for Systematic reviews and Meta-Analyses Extension for Scoping Reviews criteria were followed in this scoping review to map the available data on the association between HTR2A polymorphisms and outcomes. We identified 28 studies published before May 2025. Several studies reported that the rs6311 A allele was more frequently associated with improved treatment response, whereas the G allele was linked to poorer or absent response. In contrast, rs6313 exhibited heterogeneous patterns, with some studies reporting poorer response associated with the C allele and others reporting improved response associated with the T allele. This variability across studies likely reflects differences related to specific AAPs, as well as variations in study design and outcome definitions, rather than population or ethnicity-specific biological effects. Overall, HTR2A variants may contribute to interindividual variability in response to AAPs in schizophrenia. However, the current evidence remains insufficient for clinical application and requires further validation in well-designed and adequately powered studies.