Publications by authors named "Bernard Gagne"

Objective: Tryptophan hydroxylase is the rate-limiting enzyme in the serotonin biosynthetic pathway and plays an important role in the regulation of serotonin levels. Recently, a brain-specific isoform, tryptophan hydroxylase 2 or n-tryptophan hydroxylase, has been discovered. Some studies reported genetic and functional associations between this isoform and bipolar disorder and/or major depressive disorder.

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The P2RX7 gene is located within a region on chromosome 12q24.31 that has been identified as a susceptibility locus for affective disorders by linkage and association studies. P2RX7 is a purinergic ATP-binding calcium channel expressed in neurons as well as in microglial cells in various brain regions.

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Previous results from our genetic analyses using pedigrees from a French Canadian population suggested that the interval delimited by markers on chromosome 12, D12S86 and D12S378, was the most probable genomic region to contain a susceptibility gene for affective disorders. Association studies with microsatellite markers using a case/control sample from the same population (n = 427) revealed significant allelic associations between the bipolar phenotype and marker NBG6. Since this marker is located in intron 9 of the P2RX7 gene, we analyzed the surrounding genomic region for the presence of polymorphisms in regulatory, coding and intron/exon junction sequences.

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Previous results from our genetic analyses using pedigrees from a French Canadian population suggested that the interval delimited by markers D12S86 and D12S378 on chromosome 12 was the most probable genomic region to contain a susceptibility gene for affective disorders. Here we present a more detailed genetic analysis of a 7.7 Mb genomic region located on 12q24.

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Bipolar disorder (BP) is a psychiatric illness with both genetic and environmental components occurring with a prevalence of slightly more than 1%. Our previous linkage and case/control studies have pointed to a susceptibility locus for BP in the 12q24.31 chromosomal region.

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A very large pedigree derived from the Saguenay-Lac-St-Jean region of Quebec contains a branch where a distal chromosome 5q haplotype seems to cosegregate with bipolar affective disorder. The authors used a diagnosis model where Bipolar Types I and II and schizoaffective disorder bipolar type were considered as affected, while single or recurrent episode major depression was classified as unknown and all the others diagnoses as unaffected. Model-free two-point LOD score values of 3.

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