The CARTaGENE (CaG) study is both a population-based biobank and the largest ongoing prospective health study of men and women in Quebec. In population-based cohorts, participants are not recruited for a particular disease but represent a random selection among the population, minimizing the need to correct for bias in measured phenotypes. CaG targeted the segment of the population that is most at risk of developing chronic disorders, that is 40-69 years of age, from four metropolitan areas in Quebec. Over 20,000 participants consented to visiting 1 of 12 assessment sites where detailed health and socio-demographic information, physiological measures and biological samples (blood, serum and urine) were captured for a total of 650 variables. Significant correlations of diseases and chronic conditions are observed across these regions, implicating complex interactions, some of which we describe for major chronic conditions. The CaG study is one of the few population-based cohorts in the world where blood is stored not only for DNA and protein based science but also for gene expression analyses, opening the door for multiple systems genomics approaches that identify genetic and environmental factors associated with disease-related quantitative traits. Interested researchers are encouraged to submit project proposals on the study website (www.cartagene.qc.ca).

We completed a genome-wide scan for susceptibility loci for bipolar affective disorders in families derived from a rather homogeneous population in the Province of Québec. The genetic homogeneity of this population stems from the migration of founding families into this relatively isolated area of Québec in the 1830s. A possible founder effect, combined with a prevalence of very large families, makes this population ideal for linkage studies. Genealogies for probands can be readily constructed from a population database of acts of baptism and marriage from the early 1830s up to the present time (the BALSAC register). We chose probands with a DSM III diagnosis of bipolar affective disorder and who may be grouped within large families having genealogical origins with the founding population of the Saguenay-Lac-St-Jean area. Living members (n approximately 120) of a very large pedigree were interviewed using the Structured Clinical Interview for DSM III (SCID I), SCID II, and with a family history questionnaire. A diagnostic panel evaluated multisource information (interview, medical records, family history) and pronounced best-estimate consensus diagnoses on all family members. Linkage, SimAPM, SimIBD, and sib-pair analyses have been performed with 332 microsatellite probes covering the entire genome at an average spacing of 11 cM. GENEHUNTER and haplotype analyses were performed on regions of interest. Analysis of a second large pedigree in the same regions of interest permitted confirmation of presumed linkages found in the region of chromosome 12q23-q24.

Objective: This paper presents the results of the first public consultation for the creation of a large-scale genetic database, the Quebec CARTaGENE project. A consultation has been undertaken in order to gauge whether the general public is receptive to the project. An integral part of the approach of the researchers is to establish a dialogue with the public. Methods: Two independent expert groups have carried out qualitative and quantitative studies measuring knowledge of and interest in genetics, incentives and obstacles to CARTaGENE participation and comprehension and evaluation of the communication tools. Results: CARTaGENE is seen to hold promise for the greater population. However, reported across qualitative and quantitative studies is the concern for confidentiality and respect for the individual, transparency, the donor’s right to feedback and governance. Participation would be conditional on a response to those concerns and a greater dissemination of information. Conclusion: Community engagement in genetic research requires targeted communications, with an appropriate proportioning of information and communication, and a consideration of the ‘values and personal interests’ of individuals according to different societal segments.

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Founder effects are largely responsible for changes in frequency profiles of genetic variants in local populations or isolates. They are often recognized by elevated incidence of certain hereditary disorders as observed in regions of Charlevoix and Saguenay-Lac-Saint-Jean (SLSJ) in Northeastern Quebec. Dominantly transmitted myotonic dystrophy (DM1) is highly prevalent in SLSJ where its carrier rate reaches 1/550, compared with 1/5,000 to 1/50,000 elsewhere. To shed light on the origin of DM1 in this region, we have screened 50 nuclear DM1 families from SLSJ and studied the genetic variation in a 2.05 Mb (2.9 cM) segment spanning the site of the expansion mutation. The markers analyzed included 22 biallelic SNPs and two microsatellites. Among 50 independent DM1 chromosomes, we distinguished ten DM1-associated haplotypes and grouped them into three haplotype families, A, B and C, based on the relevant extent of allele sharing between them. To test whether the data were consistent with a single entry of the mutation into SLSJ, we evaluated the age of the founder effect from the proportion of recombinant haplotypes. Taking the prevalent haplotype A1_21 (58%) as ancestral to all the disease-associated haplotypes in this study, the estimated age of the founder effect was 19 generations, long predating the colonization of Nouvelle-France. In contrast, considering A1_21 as ancestral to the haplotype family A only, yielded the estimated founder age of nine generations, consistent with the settlement of Charlevoix at the turn of 17th century and subsequent colonization of SLSJ. We conclude that it was the carrier of haplotype A (present day carrier rate of 1/730) that was a "driver" of the founder effect, while minor haplotypes B and C, with corresponding carrier rates of 1/3,000 and 1/10,000, respectively, contribute DM1 to the incidence level known in other populations. Other studies confirm that this might be a general scenario in which a major "driver" mutation/haplotype issued from a founder effect is found accompanied by distinct minor mutations/haplotypes occurring at background population frequencies.

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