Analysis of associations between pharmacodynamic genetic factors and antipsychotics’ effectiveness and safety in adolescents with acute psychotic episodes taking antipsychotics during a 28-day follow-up

Abstract

Introduction. Antipsychotics are the main drugs for treatment of schizophrenia spectrum disorders. Pharmacodynamic genetic factors are being actively studied to improve the accuracy of antipsychotic selection based on pharmacogenetic testing.Purpose of this study: to establish associations of genetic polymorphisms of the DRD2, DRD3, DRD4, HTR2A, COMT, ZNF804A, and ANKS1B genes with the efficacy and safety of antipsychotics in adolescents with an acute psychotic episode during a 28-day follow-up.Materials and methods. The study included 68 adolescents with an established diagnosis of acute polymorphic psychotic disorder at the time of admission (F23.0-9 according to ICD-10). All patients received an antipsychotic as their main therapy. Patients were monitored for 28 days. The effectiveness of antipsychotics was assessed using the Children’s Global Assessment Scale (CGAS), Positive and Negative Symptoms Scale (PANSS), Clinical Global Impression Severity (CGI-S) and Improvement (CGI-I). The safety of pharmacotherapy was assessed using the UKU Side Effects Rating Scale (UKU SERS), Sympson-Angus Scale (SAS), Barnes Akathisia rating scale (BARS). From each patient we obtained a buccal scraped epithelium, extracted DNA from it by sorbent method and detected carriage of genetic polymorphisms DRD2 rs1800497 (C>T), DRD3 rs6280 (C>T), DRD3 rs324026 (C>T), DRD4 rs1800955 (C>T), HTR2A rs6313 (T>C), COMT rs4680 (Val158Met, G>A), ZNF804A rs1344706 (A>C), ANKS1B rs7968606 (C>T) by real-time PCR.Results. DRD2 rs1800497 T allele carriers had a stronger reduction in the PANSS subscore «Productive Symptomatics» on day 14 (Me=-7.0 [-9.0;-5.0] vs Me=-7.0 [-8.0;-2.0]; p=0.018) and day 28 of follow-up (Me=-11.0 [-9.0;-5.5] vs Me=-8.0 [-8.0;-2.0]; p=0.019). Also, greater improvement on the CGAS scale on day 14 of follow-up was seen in TC+CC HTR2A rs6313 carriers (Me=2.0 [1.0;3.0] vs. Me=2.0 [1.0;2.0]; p=0.029). DRD3 rs324026 homozygous carriers (TT) had a significantly lower SAS score (Me=0.5 [0.0; 1.0] vs. Me=1.0 [0.0; 5.0]; p=0.016) and UKU subscore «Neurological Disorders» on 28 days of antipsychotic therapy (Me=0.0 [0.0; 0.0] vs. Me=1.0 [0.0; 3.8]; p=0.005). DRD3 rs324026 TT carriers also had lower severity of akathisia according to the BARS scale. Carriers of the T DRD4 rs1800955 allele had a higher SAS scale score on day 28 of therapy compared with CC homozygotes (Me=1.0 [0.0;4.0] vs Me=0.0 [0.0;1.0]; p=0.036).Conclusion. The DRD2 rs1800497 was a predictor of better reduction of productive symptoms; HTR2A rs6313 demonstrated a similar association. The DRD2 rs1800497 polymorphic variant was a predictor of better reduction of productive symptomatology; HTR2A rs6313 demonstrated a similar association. DRD3 rs324026 and HTR2A rs6313 were associated with a lower frequency of neurological adverse reactions and akathisia. In contrast, carriers of the DRD4 rs1800955 were more prone to adverse reactions on pharmacotherapy.