Study Report

Reference	Papagni, S. A.,2011 PMID: 21421061
Citation	Papagni, S. A., A. Mechelli, et al. (2011). "Differential effects of DAAO on regional activation and functional connectivity in schizophrenia, bipolar disorder and controls." Neuroimage 56(4): 2283-2291.
Disease Type	Bipolar I Disorder & Schizophrenia
Study Design	case-control
Study Type	Candidate-gene association study
Sample Size	121 subjects comprising 40 patients with schizophrenia, 33 patients with bipolar I disorder and 48 healthy volunteers
SNP/Region/Marker Size	1 SNP
Predominant Ethnicity	Caucasian
Population	British
Gender	Male/female:15/14 of genotype CC,9/10,of CT/TT in control;15/3 of CC,18/4 of CT/TT in SZ;8/11of CC,5/9 of CT/TT in BD
Age Group	Adults : Mean age(SD)(year):34.9(10.5) of genotype CC,33.5(10.9),of CT/TT in control;34.5(12.6) of CC,35.8(10.8) of CT/TT in SZ;40.1(12.2)of CC,37.0(11.9) of CT/TT in BD

Sample Diagnosis	DSM
Technique	genotyping and Magnetic resonance imaging (MRI) scans
Statistical Method	The analysis of the fMRI data was performed using Statistical Parametric Mapping (SPM5) software (Friston, 2003), running under Matlab 6.5. A 3_2_2 full-factorial ANOVA was used in which diagnostic category and genotype were modelled as between-subject factors and task difficulty was modelled as a within subject factor.To establish putative alterations in functional integration that were underlying genotype-related differences in regional activation, we used the psycho-physiological interaction (PPI)method (Friston et al., 1997).
Result Summary	In the schizophrenia group relative to the control group, patients with one or two copies of the T allele showed lower deactivation in the left precuneus and greater activation in the right posterior cingulate gyrus than patients with two copies of the C allele. This diagnosisxgenotype interaction was associated with differences in the functional connectivity of these two regions with other cortical and subcortical areas. In contrast, there were no significant effects of diagnosis or of genotype in comparisons involving bipolar patients. Our results suggest that genetic variation in DAAO has a significant impact on both regional activation and functional connectivity, and provide evidence for a diagnosis-dependent pattern of gene action.