• ADCK3 mutations with epilepsy, stroke-like episodes and ataxia: a POLG mimic? 

      Hikmat, Omar; Tzoulis, Charalampos; Knappskog, Per; Johansson, Stefan; Boman, Helge; Sztromwasser, Pawel Szymon; Lien, Espen; Brodtkorb, Eylert; Ghezzi, Daniele; Bindoff, Laurence (Peer reviewed; Journal article, 2016-07)
      Background and purpose: Defects of coenzyme Q10 (CoQ10) metabolism cause a variety of disorders ranging from isolated myopathy to multisystem involvement. ADCK3 is one of several genes associated with CoQ10 deficiency that ...
    • Assessing the Causal Relationship of Maternal Height on Birth Size and Gestational Age at Birth: A Mendelian Randomization Analysis 

      Zhang, Ge; Bacelis, Jonas; Lengyel, Candice; Teramo, Kari; Hallman, Mikko; Helgeland, Øyvind; Johansson, Stefan; Myhre, Ronny; Sengpiel, Verena; Njølstad, Pål Rasmus; Jacobsson, Bo; Muglia, Louis (Peer reviewed; Journal article, 2015-08-18)
      Background: Observational epidemiological studies indicate that maternal height is associated with gestational age at birth and fetal growth measures (i.e., shorter mothers deliver infants at earlier gestational ages with ...
    • Associations between ABO blood groups and pancreatic ductal adenocarcinoma: influence on resection status and survival 

      el Jellas, Khadija; Hoem, Dag; Hagen, Kristin Gjerde; Kalvenes, May Britt; Aziz, Sura Mohammed; Steine, Solrun; Immervoll, Heike; Johansson, Stefan; Molven, Anders (Peer reviewed; Journal article, 2017-07)
      Both serology‐based and genetic studies have reported an association between pancreatic cancer risk and ABO blood groups. We have investigated this relationship in a cohort of pancreatic cancer patients from Western Norway ...
    • Attention-deficit hyperactivity disorder shares copy number variant risk with schizophrenia and autism spectrum disorder 

      Gudmundsson, Ólafur Ó.; Walters, Gudmundur Bragi; Ingason, Andrés; Johansson, Stefan; Zayats, Tetyana; Athanasiu, Lavinia; Sønderby, Ida Elken; Gustafsson, Omar; Nawaz, Muhammad Sulaman; Jónsson, Gudbjörn F.; Jónsson, Lina; Knappskog, Per; Ingvarsdóttir, Ester; Davidsdóttir, Katrin; Djurovic, Srdjan; Knudsen, Gun Peggy Strømstad; Askeland, Ragna Bugge; Haraldsdóttir, Gyda S.; Baldursson, Gísli; Magnússon, Páll; Sigurdsson, Engilbert; Gudbjartsson, Daníel Fannar; Stéfansson, Hreinn; Andreassen, Ole Andreas; Haavik, Jan; Reichborn-Kjennerud, Ted; Stefánsson, Kári (Peer reviewed; Journal article, 2019-10-17)
      Attention-deficit/hyperactivity disorder (ADHD) is a highly heritable common childhood-onset neurodevelopmental disorder. Some rare copy number variations (CNVs) affect multiple neurodevelopmental disorders such as ...
    • B vitamin treatments modify the risk of myocardial infarction associated with a MTHFD1 polymorphism in patients with stable angina pectoris 

      Ding, Yunpeng; Pedersen, Eva Ringdal; Johansson, Stefan; Gregory III, Jesse F.; Ueland, Per Magne; Svingen, Gard Frodahl Tveitevåg; Helgeland, Øyvind; Meyer, Klaus; Fredriksen, Åse; Nygård, Ottar (Peer reviewed; Journal article, 2016-06)
      Background: Methylenetetrahydrofolate dehydrogenase (MTHFD1) catalyzes three sequential reactions that metabolize derivatives of tetrahydrofolate (THF) in folate-dependent one-carbon metabolism. Impaired MTHFD1 flux has ...
    • The Chromosome 9p21 CVD- and T2D-Associated Regions in a Norwegian Population (The HUNT2 Survey) 

      Helgeland, Øyvind; Hertel, Jens Kristoffer; Molven, Anders; Ræder, Helge; Platou, Carl Geoffrey Parrinder; Midthjell, Kristian; Hveem, Kristian; Nygård, Ottar; Njølstad, Pål R.; Johansson, Stefan (Peer reviewed; Journal article, 2015)
      Background. Two adjacent regions upstream CDKN2B on chromosome 9p21 have been associated with type 2 diabetes (T2D) and progression of cardiovascular disease (CVD).The precise location and number of risk variants have not ...
    • Common variants in the ARC gene are not associated with cognitive abilities 

      Myrum, Craig; Giddaluru, Sudheer; Jacobsen, Kaya Kvarme; Espeseth, Thomas; Nyberg, Lars; Lundervold, Astri; Haavik, Jan; Nilsson, Lars-Göran; Reinvang, Ivar; Steen, Vidar Martin; Johansson, Stefan; Wibrand, Karin; Le Hellard, Stephanie; Bramham, Clive R. (Peer reviewed; Journal article, 2015-09-03)
      Introduction: The Activity-Regulated Cytoskeleton-associated (ARC) gene encodes a protein that is critical for the consolidation of synaptic plasticity and long-term memory formation. Given ARC's key role in synaptic ...
    • DCLK1 Variants Are Associated across Schizophrenia and Attention Deficit/Hyperactivity Disorder 

      Håvik, Bjarte; Fernandes, Carla P. D.; Christoforou, Andrea; Ersland, Kari Merete; Giddaluru, Sudheer; Cichon, Sven; Steen, Vidar Martin; Hellard, Stéphanie Le; Johansson, Stefan; Bramham, Clive R.; Haavik, Jan (Peer reviewed; Journal article, 2012-04-23)
      Doublecortin and calmodulin like kinase 1 (DCLK1) is implicated in synaptic plasticity and neurodevelopment. Genetic variants in DCLK1 are associated with cognitive traits, specifically verbal memory and general cognition. ...
    • Epistatic and gene wide effects in YWHA and aromatic amino hydroxylase genes across ADHD and other common neuropsychiatric disorders: Association with YWHAE 

      Jacobsen, Kaya Kvarme; Kleppe, Rune; Johansson, Stefan; Zayats, Tetyana; Haavik, Jan (Peer reviewed; Journal article, 2015-09)
      Monoamines critically modulate neurophysiological functions affected in several neuropsychiatric disorders. We therefore examined genes encoding key enzymes of catecholamine and serotonin biosynthesis (tyrosine and tryptophan ...
    • Evaluation of four novel genetic variants affecting hemoglobin A1c levels in a population-based type 2 diabetes cohort (the HUNT2 study) 

      Hertel, Jens Kristoffer; Johansson, Stefan; Ræder, Helge; Platou, Carl G. P.; Midthjell, Kristian; Hveem, Kristian; Molven, Anders; Njølstad, Pål Rasmus (Peer reviewed; Journal article, 2011-02-04)
      <b>Background:</b> Chronic hyperglycemia confers increased risk for long-term diabetes-associated complications and repeated hemoglobin A1c (HbA1c) measures are a widely used marker for glycemic control in diabetes treatment ...
    • Exome chip analyses in adult attention deficit hyperactivity disorder 

      Zayats, Tetyana; Jacobsen, Kaya Kvarme; Kleppe, Rune; Jacob, CP; Kittel-Schneider, Sarah; Ribases, Marta; Ramos-Quiroga, JA; Richarte, Vanesa; Casas, M; Mota, NR; Grevet, EH; Klein, M; Corominas, J; Bralten, Janita; Galesloot, T; Vasquez, AA; Herms, S; Forstner, AJ; Larsson, H; Breen, G; Asherson, P; Gross-Lesch, Silke; Lesch, KP; Cichon, Sven; Gabrielsen, Maiken Elvestad; Holmen, Oddgeir Lingaas; Bau, CH; Buitelaar, Jan; Kiemeney, L; Faraone, Stephen V.; Cormand, B; Franke, Barbara; Reif, Andreas; Haavik, Jan; Johansson, Stefan (Peer reviewed; Journal article, 2016)
      Attention-deficit/hyperactivity disorder (ADHD) is a highly heritable childhood-onset neuropsychiatric condition, often persisting into adulthood. The genetic architecture of ADHD, particularly in adults, is largely unknown. ...
    • Exome Sequencing and Genetic Testing for MODY 

      Johansson, Stefan; Irgens, Henrik; Chudasama, Kishan K.; Molnes, Janne; Aerts, Jan; Knappskog, Per; Njølstad, Pål Rasmus; Roque, Francisco S.; Jonassen, Inge; Molven, Anders (Peer reviewed; Journal article, 2012-05-25)
      Context: Genetic testing for monogenic diabetes is important for patient care. Given the extensive genetic and clinical heterogeneity of diabetes, exome sequencing might provide additional diagnostic potential when standard ...
    • Expanding the toolbox of ADHD genetics. How can we make sense of parent of origin effects in ADHD and related behavioral phenotypes? 

      Zayats, Tetyana; Johansson, Stefan; Haavik, Jan (Peer reviewed; Journal article, 2015-10-16)
      Genome-wide association (GWA) studies have shown that many different genetic variants cumulatively contribute to the risk of psychiatric disorders. It has also been demonstrated that various parent-of-origin effects (POE) ...
    • FTO, Type 2 Diabetes, and Weight Gain Throughout Adult Life: A Meta-Analysis of 41,504 Subjects From the Scandinavian HUNT, MDC, and MPP Studies 

      Hertel, Jens Kristoffer; Johansson, Stefan; Sonestedt, Emily; Jonsson, Anna; Lie, Rolv Terje; Platou, Carl G. P.; Nilsson, Peter M.; Rukh, Gull; Midthjell, Kristian; Hveem, Kristian; Melander, Olle; Groop, Leif; Lyssenko, Valeriya; Molven, Anders; Orho-Melander, Marju; Njølstad, Pål Rasmus (Research report; Peer reviewed, 2011-05)
      OBJECTIVE—FTO is the most important polygene identified for obesity. We aimed to investigate whether a variant in FTO affects type 2 diabetes risk entirely through its effect on BMI and how FTO influences BMI across adult ...
    • GBA2 mutations cause a Marinesco-Sjogren-like syndrome: Genetic and biochemical studies 

      Haugarvoll, Kristoffer; Johansson, Stefan; Rodriguez, Carlos E.; Boman, Helge; Haukanes, Bjørn Ivar; Bruland, Ove; Roque, Francisco; Jonassen, Inge; Blomqvist, Maria; Telstad, Wenche; Månsson, Jan-Eric; Knappskog, Per; Bindoff, Laurence (Peer reviewed; Journal article, 2017-01-04)
      Background: With the advent new sequencing technologies, we now have the tools to understand the phenotypic diversity and the common occurrence of phenocopies. We used these techniques to investigate two Norwegian families ...
    • The genetic architecture of sporadic and multiple consecutive miscarriage 

      Laisk, Triin; Soares, Ana Luiza G.; Ferreira, Teresa; Painter, Jodie N.; Censin, Jenny C.; Laber, Samantha; Bacelis, Jonas; Chen, Chia-Yen; Lepamets, Maarja; Lin, Kuang; Liu, Siyang; Millwood, Iona Y.; Ramu, Avinash; Southcombe, Jennifer; Andersen, Marianne S.; Yang, Ling; Becker, Christian M.; Børglum, Anders D.; Gordon, Scott D.; Bybjerg-Grauholm, Jonas; Helgeland, Øyvind; Hougaard, David M.; Jin, Xin; Johansson, Stefan; Juodakis, Julius; Kartsonaki, Christina; Kukushkina, Viktorija; Lind, Penelope A.; Metspalu, Andres; Montgomery, Grant W.; Morris, Andrew P.; Mors, Ole; Mortensen, Preben B.; Njølstad, Pål Rasmus; Nordentoft, Merete; Nyholt, Dale R.; Lippincott, Margaret; Seminara, Stephanie; Salumets, Andres; Snieder, Harold; Zondervan, Krina; Werge, Thomas; Chen, Zhengming; Conrad, Donald F.; Jacobsson, Bo; Li, Liming; Martin, Nicholas G.; Neale, Benjamin M.; Nielsen, Rasmus; Walters, Robin G. (Journal article; Peer reviewed, 2020)
      Miscarriage is a common, complex trait affecting ~15% of clinically confirmed pregnancies. Here we present the results of large-scale genetic association analyses with 69,054 cases from five different ancestries for sporadic ...
    • Genome wide association study identifies variants in NBEA associated with migraine in bipolar disorder 

      Jacobsen, Kaya Kvarme; Nievergelt, Caroline M.; Zayats, Tetyana; Greenwood, Tifany A.; Anttila, Verneri; Akiskal, Hagop Souren; Haavik, Jan; Fasmer, Ole Bernt; Kelsoe, John R.; Johansson, Stefan; Ødegaard, Ketil Joachim (Peer reviewed; Journal article, 2015-10-12)
      Background. Migraine is a common comorbidity among individuals with bipolar disorder, but the underlying mechanisms for this co-occurrence are poorly understood. The aim of this study was to investigate the genetic background ...
    • Genome-wide analyses of aggressiveness in attention-deficit hyperactivity disorder 

      Brevik, Erlend Joramo; van Donkelaar, Marjolein M J; Weber, Heike; Sanchez-Mora, Cristina; Jacob, Christian; Rivero, Olga; Kittel-Schneider, Sarah; Garcia-Martinez, Iris; Aebi, Marcel; van Hulzen, Kimm; Cormand, Bru; Ramos-Quiroga, Josep A; Lesch, Klaus-Peter; Reif, Andreas; Ribases, Marta; Franke, Barbara; Posserud, Maj-Britt Rocio; Johansson, Stefan; Lundervold, Astri; Haavik, Jan; Zayats, Tetyana (Peer reviewed; Journal article, 2016-03-29)
      Aggressiveness is a behavioral trait that has the potential to be harmful to individuals and society. With an estimated heritability of about 40%, genetics is important in its development. We performed an exploratory ...
    • Genome-wide analysis of attention deficit hyperactivity disorder in Norway 

      Zayats, Tetyana; Athanasiu, Lavinia; Sønderby, Ida Elken; Djurovic, Srdjan; Westlye, Lars Tjelta; Tamnes, Christian Krog; Fladby, Tormod; Aase, Heidi; Zeiner, Pål; Reichborn-Kjennerud, Ted; Knappskog, Per; Knudsen, Gun Peggy; Andreassen, Ole Andreas; Johansson, Stefan; Haavik, Jan (Peer reviewed; Journal article, 2015-04-13)
      Background Attention deficit hyperactivity disorder (ADHD) is a highly heritable neuropsychiatric condition, but it has been difficult to identify genes underlying this disorder. This study aimed to explore genetics of ...
    • Genome-wide association study reveals dynamic role of genetic variation in infant and early childhood growth 

      Helgeland, Øyvind; Vaudel, Marc; Juliusson, Petur Benedikt; Holmen, Oddgeir Lingaas; Juodakis, Julius; Bacelis, Jonas; Jacobsson, Bo; Lindekleiv, Haakon; Hveem, Kristian; Lie, Rolv T.; Knudsen, Gun Peggy Strømstad; Stoltenberg, Camilla; Magnus, Per; Sagen, Jørn V.; Molven, Anders; Johansson, Stefan; Njølstad, Pål Rasmus (Peer reviewed; Journal article, 2019-10-01)
      Infant and childhood growth are dynamic processes with large changes in BMI during development. By performing genome-wide association studies of BMI at 12 time points from birth to eight years (9286 children, 74,105 ...