Gareth E. Davies

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The highly complex structure of the human brain is strongly shaped by genetic influences. Subcortical brain regions form circuits with cortical areas to coordinate movement, learning, memory and motivation, and altered circuits can lead to abnormal behaviour and disease. To investigate how common genetic variants affect the structure of these brain regions,(More)
Genetic variation in a population can be summarized through principal component analysis (PCA) on genome-wide data. PCs derived from such analyses are valuable for genetic association studies, where they can correct for population stratification. We investigated how to capture the genetic population structure in a well-characterized sample from the(More)
BACKGROUND Some of the genetic vulnerability for addiction may be mediated by impulsivity. This study investigated relationships among impulsivity, substance use problems and six neurexin-3 (NRXN3) polymorphisms. Neurexins (NRXNs) are presynaptic transmembrane proteins that play a role in the development and function of synapses. METHODS Impulsivity was(More)
Murine natural killer cells selectively express members of the Ly49 family of class I MHC receptors; however, the molecular mechanism controlling probabilistic expression of Ly49 proteins has not been defined. A pair of overlapping, divergent promoters discovered in the Ly49g gene functions as a molecular switch that can produce a forward transcript(More)
A promoter polymorphism in the serotonin transporter gene (5-HTTLPR) has been reported to confer relative risk for phenotypes (depression/anxiety) and endophenotypes (amygdala reactivity). In this report, we identify and characterize three rare 5-HTTLPR alleles not previously described in the human literature. The three novel alleles were identified while(More)
Weight gain is a common and potentially serious complication associated with the treatment of second generation antipsychotics such as clozapine and risperidone. Increased peripheral adipogenesis via the SREBP-1 pathway could be one critical mechanism responsible for antipsychotic drug-induced weight gain. Berberine, a botanical alkaloid, has been shown in(More)
BACKGROUND The ability to perform comprehensive profiling of cancers at high resolution is essential for precision medicine. Liquid biopsies using shed exosomes provide high-quality nucleic acids to obtain molecular characterization, which may be especially useful for visceral cancers that are not amenable to routine biopsies. PATIENTS AND METHODS We(More)
The Affymetrix Drug Metabolism Enzymes and Transporters (DMET) microarray is the first assay to offer a large representation of SNPs conferring genetic diversity across known pharmacokinetic markers. As a convenient and painless alternative to blood, saliva samples have been reported to work well for genotyping on the high density SNP arrays, but no reports(More)
The Netherlands Twin Register (NTR) began in 1987 with data collection in twins and their families, including families with newborn twins and triplets. Twenty-five years later, the NTR has collected at least one survey for 70,784 children, born after 1985. For the majority of twins, longitudinal data collection has been done by age-specific surveys. Shortly(More)
OBJECTIVE To test the association between the catechol-O-methyltransferase (COMT) Val158Met polymorphism and both aggressive behavior and attention problems in youth. We hypothesized that youth carrying a Met allele would have greater average aggressive behavior scores, and that youth exhibiting Val-homozygosity would have greater average attention problems(More)