Anthony O'Neill

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The enzyme catechol-o-methyltransferase (COMT) transfers a methyl group from adenosylmethionine to catecholamines including the neurotransmitters dopamine, epinephrine and norepinephrine. This methylation results in the degradation of catecholamines. The involvement of the COMT gene in the metabolic pathway of these neurotransmitters has made it an(More)
The hypothesis of the existence of one or more schizophrenia susceptibility loci on chromosome 22q is supported by reports of genetic linkage and association, meta-analyses of linkage, and the observation of elevated risk for psychosis in people with velocardiofacial syndrome, caused by 22q11 microdeletions. We tested this hypothesis by evaluating 10(More)
OBJECTIVE The authors used a genome-wide association study (GWAS) of multiply affected families to investigate the association of schizophrenia to common single-nucleotide polymorphisms (SNPs) and rare copy number variants (CNVs). METHOD The family sample included 2,461 individuals from 631 pedigrees (581 in the primary European-ancestry analyses).(More)
Schizophrenia is clinically heterogeneous and multidimensional, but it is not known whether this is due to etiological heterogeneity. Previous studies have not consistently reported association between any specific polymorphisms and clinical features of schizophrenia, and have primarily used case-control designs. We tested for the presence of association(More)
We conducted data-mining analyses of genome wide association (GWA) studies of the CATIE and MGS-GAIN datasets, and found 13 markers in the two physically linked genes, PTPN21 and EML5, showing nominally significant association with schizophrenia. Linkage disequilibrium (LD) analysis indicated that all 7 markers from PTPN21 shared high LD (r(2)>0.8),(More)
There is increasing evidence that a neurodevelopmental process is accountable for at least a proportion of schizophrenic cases. Brain-derived neurotrophic factor (BDNF), a member of a group of proteins that includes neurotrophin-3/4/5 and nerve growth factor (NGF), is an attractive candidate gene. We have performed a case control association study using the(More)
The dopamine D3 (DRD3) receptor gene has been implicated in the aetiology of schizophrenia as a candidate gene since it combines both the dopamine receptor and limbic hypotheses of the disease. Previous association studies of a DRD3/MscI polymorphism suggested an increased frequency of homozygosity at the DRD3 receptor gene in schizophrenia. Homozygosity(More)
Recent findings of an association between schizophrenia and a T102C polymorphism at the 5-HT2a receptor gene (particularly with genotype 1-2 and 2-2 and allele 2) prompted us to investigate this marker in familial Irish schizophrenic patients, their relatives, and ethnically matched unrelated controls; 247 probands and 249 controls were included in this(More)
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