Andreassen OA

References (3)

Title : Association of Butyrylcholinesterase-K Allele and Apolipoprotein E varepsilon4 Allele with Cognitive Decline in Dementia with Lewy Bodies and Alzheimer's Disease - Vijayaraghavan_2016_J.Alzheimers.Dis_50_567
Author(s) : Vijayaraghavan S , Darreh-Shori T , Rongve A , Berge G , Sando SB , White LR , Auestad BH , Witoelar A , Andreassen OA , Ulstein ID , Aarsland D
Ref : J Alzheimers Dis , 50 :567 , 2016
Abstract : BACKGROUND: A common polymorphism of the butyrylcholinesterase gene, the K-variant (BCHE-K) is associated with reduced butyrylcholinesterase (BuChE) activity. Insufficient studies exist regarding the frequency and role of BCHE-K in dementias. OBJECTIVE: To determine the association of BCHE-K and APOEvarepsilon4 with diagnosis and rate of cognitive decline in dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) patients.
METHODS: Genomic DNA from 368 subjects (108 AD, 174 DLB, and 86 controls) from two routine clinical cohort studies in Norway; DemVest and TronderBrain, were genotyped for BCHE-K and APOEvarepsilon4. The mild dementia DemVest subjects received annual Mini-Mental State Examination assessments for five years.
RESULTS: BCHE-K frequency was lower in DLB (33.9% ; p < 0.01) than in control subjects (51.2%), and was numerically lower in AD as well (38.9% ; p = 0.11). More rapid cognitive decline was associated with the APOEvarepsilon4 genotype, but not with the BCHE-K genotype. In an exploratory analysis of patients who completed all five follow-up visits, there was greater cognitive decline in BCHE-K carriers in the presence of the APOEvarepsilon4 allele than in the absence of these polymorphisms. CONCLUSION: BCHE-K is associated with a reduced risk for AD and DLB whereas APOEvarepsilon4 is associated with more rapid cognitive decline. The greater cognitive decline in individuals with both APOEvarepsilon4 and BCHE-K alleles require prospective confirmation in well-controlled trials.
ESTHER : Vijayaraghavan_2016_J.Alzheimers.Dis_50_567
PubMedSearch : Vijayaraghavan_2016_J.Alzheimers.Dis_50_567
PubMedID: 26757188

Title : Common variants conferring risk of schizophrenia - Stefansson_2009_Nature_460_744
Author(s) : Stefansson H , Ophoff RA , Steinberg S , Andreassen OA , Cichon S , Rujescu D , Werge T , Pietilainen OP , Mors O , Mortensen PB , Sigurdsson E , Gustafsson O , Nyegaard M , Tuulio-Henriksson A , Ingason A , Hansen T , Suvisaari J , Lonnqvist J , Paunio T , Borglum AD , Hartmann A , Fink-Jensen A , Nordentoft M , Hougaard D , Norgaard-Pedersen B , Bottcher Y , Olesen J , Breuer R , Moller HJ , Giegling I , Rasmussen HB , Timm S , Mattheisen M , Bitter I , Rethelyi JM , Magnusdottir BB , Sigmundsson T , Olason P , Masson G , Gulcher JR , Haraldsson M , Fossdal R , Thorgeirsson TE , Thorsteinsdottir U , Ruggeri M , Tosato S , Franke B , Strengman E , Kiemeney LA , Melle I , Djurovic S , Abramova L , Kaleda V , Sanjuan J , de Frutos R , Bramon E , Vassos E , Fraser G , Ettinger U , Picchioni M , Walker N , Toulopoulou T , Need AC , Ge D , Yoon JL , Shianna KV , Freimer NB , Cantor RM , Murray R , Kong A , Golimbet V , Carracedo A , Arango C , Costas J , Jonsson EG , Terenius L , Agartz I , Petursson H , Nothen MM , Rietschel M , Matthews PM , Muglia P , Peltonen L , St Clair D , Goldstein DB , Stefansson K , Collier DA
Ref : Nature , 460 :744 , 2009
Abstract : Schizophrenia is a complex disorder, caused by both genetic and environmental factors and their interactions. Research on pathogenesis has traditionally focused on neurotransmitter systems in the brain, particularly those involving dopamine. Schizophrenia has been considered a separate disease for over a century, but in the absence of clear biological markers, diagnosis has historically been based on signs and symptoms. A fundamental message emerging from genome-wide association studies of copy number variations (CNVs) associated with the disease is that its genetic basis does not necessarily conform to classical nosological disease boundaries. Certain CNVs confer not only high relative risk of schizophrenia but also of other psychiatric disorders. The structural variations associated with schizophrenia can involve several genes and the phenotypic syndromes, or the 'genomic disorders', have not yet been characterized. Single nucleotide polymorphism (SNP)-based genome-wide association studies with the potential to implicate individual genes in complex diseases may reveal underlying biological pathways. Here we combined SNP data from several large genome-wide scans and followed up the most significant association signals. We found significant association with several markers spanning the major histocompatibility complex (MHC) region on chromosome 6p21.3-22.1, a marker located upstream of the neurogranin gene (NRGN) on 11q24.2 and a marker in intron four of transcription factor 4 (TCF4) on 18q21.2. Our findings implicating the MHC region are consistent with an immune component to schizophrenia risk, whereas the association with NRGN and TCF4 points to perturbation of pathways involved in brain development, memory and cognition.
ESTHER : Stefansson_2009_Nature_460_744
PubMedSearch : Stefansson_2009_Nature_460_744
PubMedID: 19571808

Title : Association analysis of schizophrenia on 18 genes involved in neuronal migration: MDGA1 as a new susceptibility gene - Kahler_2008_Am.J.Med.Genet.B.Neuropsychiatr.Genet_147B_1089
Author(s) : Kahler AK , Djurovic S , Kulle B , Jonsson EG , Agartz I , Hall H , Opjordsmoen S , Jakobsen KD , Hansen T , Melle I , Werge T , Steen VM , Andreassen OA
Ref : American Journal of Medicine Genet B Neuropsychiatr Genet , 147B :1089 , 2008
Abstract : Several lines of evidence support the theory of schizophrenia (SZ) being a neurodevelopmental disorder. The structural, cytoarchitectural and functional brain abnormalities reported in patients with SZ, might be due to aberrant neuronal migration, since the final position of neurons affects neuronal function, morphology, and formation of synaptic connections. We have investigated the putative association between SZ and gene variants engaged in the neuronal migration process, by performing an association study on 839 cases and 1,473 controls of Scandinavian origin. Using a gene-wide approach, tagSNPs in 18 candidate genes have been genotyped, with gene products involved in the neuron-to-glial cell adhesion, interactions with the DISC1 protein and/or rearrangements of the cytoskeleton. Of the 289 markers tested, 19 markers located in genes MDGA1, RELN, ITGA3, DLX1, SPARCL1, and ASTN1, attained nominal significant P-values (P < 0.05) in either a genotypic or allelic association test. All of these genes, except transcription factor DLX1, are involved in the adhesion between neurons and radial glial cells. Eight markers obtained nominal significance in both tests, and were located in intronic or 3'UTR regions of adhesion molecule MDGA1 and previously reported SZ candidate RELN. The most significant result was attained for MDGA1 SNP rs9462341 (unadjusted association results: genotypic P = 0.00095; allelic P = 0.010). Several haplotypes within MDGA1, RELN, ITGA3, and ENAH were nominally significant. Further studies in independent samples are needed, including upcoming genome wide association study results, but our data suggest that MDGA1 is a new SZ susceptibility gene, and that altered neuronal migration is involved in SZ pathology.
ESTHER : Kahler_2008_Am.J.Med.Genet.B.Neuropsychiatr.Genet_147B_1089
PubMedSearch : Kahler_2008_Am.J.Med.Genet.B.Neuropsychiatr.Genet_147B_1089
PubMedID: 18384059