Study Report

Reference	Curtis, D.,2011 PMID: 21057379
Citation	Curtis, D., A. E. Vine, et al. (2011). "Case-case genome-wide association analysis shows markers differentially associated with schizophrenia and bipolar disorder and implicates calcium channel genes." Psychiatr Genet 21(1): 1-4.
Disease Type	Bipolar I Disorder & Schizophrenia
Study Design	case-case
Study Type	Genome-wide association study
Sample Size	506 patients with bipolar 1 disorder, 523 patients with schizophrenia and 505 controls.
SNP/Region/Marker Size	302,482 SNPs
Predominant Ethnicity	Caucasian
Population	British

Sample Diagnosis	RDC
Sample Status	The research has received UK NHS Multicentre Research Ethics Committee (MREC) approval from the London Metropolitan MREC.Subjects were recruited on the basis of having European, non-Jewish ancestry and at least three grand-parents who were from the UK with the fourth possibly coming from a different European country as defined before the 2004 enlargement. All subjects were interviewed using the lifetime version of the Schizophrenia and Affective Disorders Schedule and assigned a Research Diagnostic Criteria diagnosis.
Technique	genotyping(Affymetrix 500K array)
Statistical Method	For these markers, allele frequencies were compared between bipolar disorder and schizophrenia using a two-by-two chi-squared test.
Result Summary	RESULTS: Eight markers were significant at P value of less than 10(-5). Of these, the most interesting finding was for rs17645023, which was significant at P value of less than 10(-6) and which lies 36 kb from CACNG5. Control allele frequencies for this marker were intermediate between those for bipolar and schizophrenic cases. CONCLUSION: The application of this approach suggests that it does have some merits. The finding for CACNG5, taken together with the earlier implication of CACNA1C and CACNA1B, strongly suggests a key role for voltage-dependent calcium channel genes in the susceptibility to bipolar disorder and/or schizophrenia.