Grant: Operating Grant

Genetic and environmental factors are undoubtedly in cause in the origins of schizophrenia (SZ) and bipolar disorder (BP) diseases. The clinical manifestations of these disorders are varied and complex, which enhances the difficulty to identify the genes involved. For 20 years, our research team gathered a sample of 1300 members from 48 well-characterized multigenerational families of Eastern Quebec that are densely affected by SZ or BP, in which we were able to identify 10 different chromosome regions where should be located the genes at the origin of the disease. However, our results provided relatively large chromosomal regions including some 1500 genes from which should be identified the true causal genes. The global objective of the current proposal is to identify, among these 1500 genes, those responsibles for our observed linkage signals using a genomic approach. Through the analysis of gene expression and genetic association, we will be able to set apart the causal candidate genes located in the 10 chromosomal regions having shown linkage in our kindred samples. These recent progresses represent the beginning of a new era for psychiatry leading hopefully to three revolutions in our field: i) The development of new treatments based on the understanding of pathophysiology rather than on fortuitous findings. ii) The development of biological diagnostic tests which, in combination with clinical assessments, will support efforts for an earlier identification of cases in order to rapidly initiate treatment and avoid chronicity. iii) The possibility of identifying environmental factors interacting with susceptibility genes that cause psychiatric disorders, paving the way to preventive interventions.