Article

Genome-wide association study of patient-rated and clinician-rated global impression of severity during antipsychotic treatment

aCenter for Biomarker Research and Personalized Medicine, School of Pharmacy, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia bDepartments of Genetics, Psychiatry & Epidemiology, University of North Carolina at Chapel Hill, North Carolina, USA cDepartment of General Biology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil dDepartment of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
Pharmacogenetics and Genomics (Impact Factor: 3.45). 12/2012; 23(2). DOI: 10.1097/FPC.0b013e32835ca260
Source: PubMed

ABSTRACT OBJECTIVE: To examine the unique and congruent findings between multiple raters in a genome-wide association study (GWAS) in the context of understanding individual differences in treatment response during antipsychotic therapy for schizophrenia. MATERIALS AND METHODS: We performed GWAS to search for genetic variation affecting treatment response. The analysis sample included 738 patients with schizophrenia, successfully genotyped for ∼492k single nucleotide polymorphisms (SNPs) from the Clinical Antipsychotic Trial of Intervention Effectiveness. Outcomes included both clinician and patient report of illness severity on global impression scales, the clinical global impression severity scale and patient global impression, respectively. Our criterion for genome-wide significance was a prespecified threshold ensuring that, on average, only 10% of the significant findings are false discoveries. RESULTS: Thirteen SNPs reached genome-wide significance. The top findings indicated three SNPs in PDE4D, 5q12.1 (P=4.2×10, 1.6×10, 1.8×10), mediating the effects of quetiapine on patient-reported severity and an additional three SNPs in TJP1, 15q13.1 (P=2.25×10, 4.86×10, 4.91×10), mediating the effects of risperidone on patient-reported severity. For clinician-reported severity, two SNPs in PPA2, 4q24 (P=3.68×10, 5.05×10), were found to reach genome-wide significance. CONCLUSION: We found evidence of both a novel and a consistent association when examining the results from the patient and clinician ratings, suggesting that different raters may capture unique facets of schizophrenia. Although our findings require replication and functional validation, this study shows the potential of GWAS to discover genes that potentially mediate treatment response of antipsychotic medication.

Download full-text

Full-text

Available from: Joseph L. McClay, Jan 30, 2015
1 Follower
 · 
120 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Schizophrenia is a severe disorder that significantly affects the quality of life and total functioning of patients and their caregivers. Clozapine is the first atypical antipsychotic with fewer adverse effects and established efficacy. As a rule of thumb, risperidone is one of the most reliable and effective antipsychotics for newly diagnosed and chronic schizophrenics. Pharmacogenetic studies have identified genomic variants of candidate genes that seem to be important in the way a patient responds to treatment. The recent progress made in pharmacogenomics will improve the quality of treatment, since drug doses will be tailored to the special needs of each patient. In this article, we review the available literature attempting to delineate the role of genomic variations in clozapine and risperidone response in schizophrenic patients of various ethnicities. We conclude that pharmacogenomics for these two drugs is still not ready for implementation in the clinic.
    Pharmacogenomics 01/2014; 15(1):95-110. DOI:10.2217/pgs.13.219 · 3.43 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This review considers pharmacogenetics of the so called 'second-generation' antipsychotics. Findings for polymorphisms replicating in more than one study are emphasized and compared and contrasted with larger-scale candidate gene studies and genome-wide association study analyses. Variants in three types of genes are discussed: pharmacokinetic genes associated with drug metabolism and disposition, pharmacodynamic genes encoding drug targets, and pharmacotypic genes impacting disease presentation and subtype. Among pharmacokinetic markers, CYP2D6 metabolizer phenotype has clear clinical significance, as it impacts dosing considerations for aripiprazole, iloperidone and risperidone, and variants of the ABCB1 gene hold promise as biomarkers for dosing for olanzapine and clozapine. Among pharmacodynamic variants, the TaqIA1 allele of the DRD2 gene, the DRD3 (Ser9Gly) polymorphism, and the HTR2C -759C/T polymorphism have emerged as potential biomarkers for response and/or side effects. However, large-scale candidate gene studies and genome-wide association studies indicate that pharmacotypic genes may ultimately prove to be the richest source of biomarkers for response and side effect profiles for second-generation antipsychotics.
    Pharmacogenomics 04/2014; 15(6):869-884. DOI:10.2217/pgs.14.50 · 3.43 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Genomic research is one of the tools for elucidating the pathogenesis of diseases of global health relevance and paving the research dimension to clinical and public health translation. Recent advances in genomic research and technologies have increased our understanding of human diseases, genes associated with these disorders, and the relevant mechanisms. Genome-wide association studies (GWAS) have proliferated since the first studies were published several years ago and have become an important tool in helping researchers comprehend human variation and the role genetic variants play in disease. However, the need to expand the diversity of populations in GWAS has become increasingly apparent as new knowledge is gained about genetic variation. Inclusion of diverse populations in genomic studies is critical to a more complete understanding of human variation and elucidation of the underpinnings of complex diseases. In this review, we summarize the available data on GWAS in recent African ancestry populations within the western hemisphere (i.e. African Americans and peoples of the Caribbean) and continental African populations. Furthermore, we highlight ways in which genomic studies in populations of recent African ancestry have led to advances in the areas of malaria, HIV, prostate cancer, and other diseases. Finally, we discuss the advantages of conducting GWAS in recent African ancestry populations in the context of addressing existing and emerging global health conditions.
    Public Health Genomics 11/2014; 18(1). DOI:10.1159/000367962 · 2.46 Impact Factor
Show more