Study Report

Reference	Saito, T.,2003 PMID: 12497619
Citation	Saito, T., P. Stopkova, et al. (2003). "Polymorphism screening of PIK4CA: possible candidate gene for chromosome 22q11-linked psychiatric disorders." Am J Med Genet B Neuropsychiatr Genet 116B(1): 77-83.
Disease Type	Bipolar Disorder & Schizophrenia
Study Design	case-control
Study Type	Candidate-gene association study
Sample Size	134 controls,133 BD patients and 100 SZ patients
SNP/Region/Marker Size	3 variants
Predominant Ethnicity	Caucasian
Population	American

Sample Diagnosis	RDC
Sample Status	Patients with BPD were diagnosed on the basis of either a SADS-L interview or by unstructured clinical interview modified from SADS-L that yielded diagnostic information enabling the diagnosis of BPD using RDC criteria [Spitzer et al., 1978]. Patients with either bipolar disorder I (BPI) or bipolar disorder II (BPII) were included in the study. The patients were recruited from clinics and private practices affiliated with the Albert Einstein College of Medicine. Forty-three subjects were unrelated patients with BPI obtained from the Coriell Institute in conjunction with the National Institutes of Mental Health Bipolar Genetics Initiative. Patients with schizophrenia were recruited from the Bronx Psychiatric Center, Long Island Jewish Hillside Hospital and Rockland State Hospital. The diagnosis was established by RDC criteria using SCID (LIJ) or clinical interview (Rockland State Hospital, Bronx Psychiatric Center). Patients signed an informed consent approved by the local Committee on Clinical Investigation. Control subjects were anonymous blood bank donors. No formal testing procedure was used to screen controls for underlying psychiatric illness. All patients and controls were Caucasian.
Technique	genotyping
Statistical Method	the Pearson X2 test
Result Summary	There was no difference in the allele distribution in mentally ill subjects and controls for two variants, R2259C and E2079Q, both located in the PIK4CA catalytic domain. There was, however, a trend toward significance in the distribution of the -31 promoter genotypes in bipolar subjects and controls. Although the results of this analysis were modest, considering the heterogeneity of BPD and SZ and the hypothesis that BPD may be caused by abnormalities in genes that regulate PI-mediated phenomena in the brain, the polymorphisms we detected in the PIK4CA gene should be analyzed in a larger data set to help determine their significance in 22q11-linked mental disorders.