SULT4A1 haplotype: conflicting results on its role as a biomarker of antipsychotic response

Aim: Based on previous pharmacogenetic findings, we investigated the possible association between SULT4A1-1 haplotype and antipsychotic treatment response. Materials & methods: Using Mixed Model Repeated Measures, we tested the relationship between SULT4A1-1 status (+ carrier, - noncarrier) and clinical improvement (in Positive and Negative Syndrome Scale total score) among European ancestry patients treated with paliperidone extended release (n = 937), paliperidone palmitate (n = 990), risperidone (n = 507) and olanzapine (n = 381) in 12 schizophrenia, two schizoaffective disorder and three bipolar I disorder trials. SULT4A1-1 haplotype was determined using tagging SNP rs763120. Results: There was no significant difference between SULT4A1-1(+) and SULT4A1-1(-) patients for treatment response to paliperidone or olanzapine. SULT4A1-1(-) patients had better treatment response to risperidone in one schizophrenia trial, but not in another schizophrenia trial or bipolar mania trial. Conclusion: Across three psychiatric disorders (n = 2815 patients), we observed no consistent association between SULT4A1-1 status and atypical antipsychotic effect. Original submitted 11 February 2014; Revision submitted 2 July 2014