rs6438552

This systematic review of 98 studies examined biological predictors of clozapine response in treatment-resistant schizophrenia patients. Of 379 different gene variants investigated across 70 genetic studies, only three variants (DRD3 Ser9Gly rs6280, HTR2A His452Tyr, and GNB3 C825T) achieved independent replication. Non-genetic predictors included higher prefrontal cortical volumes and lower HVA:5-HIAA ratio in cerebrospinal fluid.

A targeted sequencing study of 115 patients with bipolar disorder and depression identified genetic variants in NRG1, PIP4K2A, and HTR2C associated with treatment response and disease severity. The allele C of rs35641374 (NRG1) was associated with longer intervals between depressive episodes (p=4.37e-07), while the allele C of rs10508649 (PIP4K2A) was associated with longer intervals between manic/mixed episodes (p=0.000309) and treatment resistance assessed by CGI-I scale (p=0.000943). The allele A of rs2248440 (HTR2C) was associated with higher depression severity (p=0.003).

This targeted sequencing association study of 115 psychiatric patients and 34 controls identifies NRG1, PIP4K2A, and HTR2C as candidate biomarker genes for antidepressant treatment response and mood disorder recurrence. Key findings include rs35641374 (NRG1) associated with longer time to depressive recurrence in bipolar disorder (p=4.37e-07), rs61731109 and rs10508649 (PIP4K2A) associated with antidepressant non-response (p=0.00111 and p=0.000943), and rs2248440 (HTR2C) associated with higher depression severity (p=0.003).

A systematic review of 98 studies investigating biological predictors of clozapine response in treatment-resistant schizophrenia. Of 70 genetic studies examining 379 variants, only three genetic variants have independently replicated findings: DRD3 Ser9Gly (rs6280), HTR2A His452Tyr, and GNB3 C825T (rs5442/rs5443). Non-genetic predictors include higher prefrontal cortical structural integrity and activity, and lower HVA:5-HIAA ratio in cerebrospinal fluid.

A case-control and family-based association study examining 12 genetic markers across the GSK3β gene for association with schizophrenia and clozapine response. Three markers showed significant genotypic association with schizophrenia in the case-control sample: rs7624540 (χ² = 8.28, p = 0.016), rs4072520 (χ² = 9.94, p = 0.007), and rs6779828 (χ² = 6.83, p = 0.033). No associations were found in family-based analysis or with clozapine treatment response.