title: CRY1 Variations Impacts on the Depressive Relapse Rate in a Sample of Bipolar Patients.
abstract: OBJECTIVE
  A relevant part of the social and personal burden caused by Bipolar Disorder (BD) is related to depressive phases. Authors investigated the genetic impact of a set of variations located in CRY1, a gene involved in the control of the circadian rhythms, towards depressive episodes in a sample of bipolar patients from the STEP-BD sample. As a secondary analysis, CYR1 variations were analyzed as predictors of sleep disruption.
  
  
  METHODS
  654 bipolar patients were included in the analysis. Data were available genome-wide. The part of the genome coding for the CRY1 was imputed and pruned according to standards in the field. 7 SNPs were available for the analysis. A correction for multitesting was applied and we had sufficient power (0.80) to detect a small-medium effect size (0.22) between two allelic frequencies each one represented by at least 300 subjects.
  
  
  RESULTS
  Intronic rs10861688 was associated with the number of depressive events corrected for the times patients were assessed during the period of observation. In particular, AA subjects (n=21) had 4.46±3.15 events, AG (n=141) had 3.08±3.17 and GG (n=342) 2.65±2.97 (p=0.0048, beta=-0.22). No other significant associations were reported.
  
  
  CONCLUSIONS
  We bring further evidence that genes involved in the regulation of circadian rhythms may be relevant to depressive bipolar phases. Independent confirmation analyses are mandatory.
authors: I.R.C.C.S. "San Giovanni di Dio", Fatebenefratelli, Brescia, Italy.
authors: Antonio
authors: A
authors: Drago
authors: Department of Pharmacy and Biotechnologies, University of Bologna, Bologna, Italy.
authors: Barbara
authors: B
authors: Monti
authors: Department of Biomedical and Neuromotor Sciences - DIBINEM -, University of Bologna, Bologna, Italy.
authors: Diana
authors: D
authors: De Ronchi
authors: Department of Biomedical and Neuromotor Sciences - DIBINEM -, University of Bologna, Bologna, Italy.
authors: Alessandro
authors: A
authors: Serretti
keywords: Bipolar disorder; CRY1; Depressive episode; Gene; SNP