Study Report

Reference	Galimberti, D.,2012 PMID: 22505994
Citation	Galimberti, D., B. Dell'Osso, et al. (2012). "Progranulin gene variability and plasma levels in bipolar disorder and schizophrenia." PLoS One 7(4): e32164.
Disease Type	Bipolar Disorder & Schizophrenia
Study Design	case-control
Study Type	Candidate-gene association study
Sample Size	patients with schizophrenia (n = 271) or BPD (n = 237) as compared with 574 age-, gender- and ethnicity matched controls
SNP/Region/Marker Size	5 SNPs
Predominant Ethnicity	Caucasian
Population	German
Gender	Male:female:unknown:83:153:1 in BPD patients,146:120:5 in SZ patients and 230:341:3 in control group
Age Group	Adults : Mean age(SEM)(year):27.4(0.39) for control subjects,27.13(0.59) for SZ patients and 30.14(0.76) for BPD patients

Sample Diagnosis	DSM
Sample Status	Five hundreds and eight patients with psychiatric disorders were recruited at the Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wurzburg, Germany. Two hundreds seventy one patients were diagnosed with schizophrenia, whereas 237 patients were diagnosed with BPD (type 1: n= 103,type 2: n = 78, not defined: n= 56).The control group was recruited at the Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wurzburg, Germany. The age of controls did not significantly differ from that of patients' age at disease onset (P>0.05). The control sample was composed of blood donors, staff members, and volunteers all originating from the Lower Franconia region. The sample was not systematically screened for psychiatric disorders; however, all subjects were free of medication, and the study was explained to them, so that the likelihood of severe psychiatric disorders in the control sample was low.
Technique	Genotyping
Statistical Method	Chi square test
Result Summary	A significantly decreased allelic frequency of the minor versus the wild-type allele was observed for rs2879096 (23.2 versus 34.2%, P<0.001, OR:0.63, 95%CI:0.49-0.80), rs4792938 (30.7 versus 39.7%, P = 0.005, OR: 0.70, 95%CI: 0.55-0.89) and rs5848 (30.3 versus 36.8, P = 0.007, OR: 0.71, 95%CI: 0.56-0.91). Mean+/-SEM progranulin plasma levels were significantly decreased in BPD patients, either Germans or Italians, as compared with controls (89.69+/-3.97 and 116.14+/-5.80 ng/ml, respectively, versus 180.81+/-18.39 ng/ml P<0.001) and were not correlated with age.In conclusion, GRN variability decreases the risk to develop BPD and schizophrenia, and progranulin plasma levels are significantly lower in BPD patients than in controls. Nevertheless, a larger replication analysis would be needed to confirm these preliminary results.