Browsing by Subject "PHENOTYPES"

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  • Bauer, Witold; Veijola, Riitta; Lempainen, Johanna; Kiviniemi, Minna; Härkönen, Taina; Toppari, Jorma; Knip, Mikael; Gyenesei, Attila; Ilonen, Jorma (2019)
    Context: Children with initial autoantibodies to either insulin (IAA) or glutamic acid decarboxylase (GADA) differ in peak age of seroconversion and have different type 1 diabetes (T1D) risk gene associations, suggesting heterogeneity in the disease process. Objective: To compare the associations of age at seroconversion, HLA risk, and specificity of secondary autoantibodies with the progression of islet autoimmunity between children with either IAA or GADA as their first autoantibody. Design and methods: A cohort of 15,253 children with HLA-associated increased risk of T1D participated in a follow-up program in which islet autoantibodies were regularly measured. The median follow-up time was 6.7 years. Spearman correlation, Kaplan-Meier survival plots, and Cox proportional-hazard models were used for statistical analyses. Results: Persistent positivity for at least one of the tested autoantibodies was detected in 998 children; 388 of children progressed to clinical T1D. Young age at initial seroconversion was associated with a high probability of expansion of IAA-initiated autoimmunity and progression to clinical diabetes, whereas expansion of GADA-initiated autoimmunity and progression to diabetes were not dependent on initial seroconversion age. The strength of HLA risk affected the progression of both IAA- and GADA-initiated autoimmunity. The simultaneous appearance of two other autoantibodies increased the rate of progression to diabetes compared with that of a single secondary autoantibody among subjects with GADA-initiated autoimmunity but not among those with IAA as the first autoantibody. Conclusions: Findings emphasize the differences in the course of islet autoimmunity initiated by either IAA or GADA supporting heterogeneity in the pathogenic process.
  • Pakkasela, Johanna; Ilmarinen, Pinja; Honkamäki, Jasmin; Tuomisto, Leena E.; Andersen, Heidi; Piirilä, Päivi; Hisinger-Mölkänen, Hanna; Sovijärvi, Anssi; Backman, Helena; Lundbäck, Bo; Rönmark, Eva; Kankaanranta, Hannu; Lehtimäki, Lauri (2020)
    Background Onset of allergic asthma has a strong association with childhood but only a few studies have analyzed incidence of asthma from childhood to late adulthood in relation to allergy. The purpose of the study was to assess age-specific incidence of allergic and non-allergic asthma. Methods Questionnaires were sent to 8000 randomly selected recipients aged 20-69 years in Finland in 2016. The response rate was 52.3% (n = 4173). The questionnaire included questions on e.g. atopic status, asthma and age at asthma diagnosis. Asthma was classified allergic if also a physician-diagnosed allergic rhinitis was reported. Results The prevalence of physician-diagnosed asthma and allergic rhinitis were 11.2 and 17.8%, respectively. Of the 445 responders with physician-diagnosed asthma, 52% were classified as allergic and 48% as non-allergic. Median ages at diagnosis of allergic and non-allergic asthma were 19 and 35 years, respectively. Among subjects with asthma diagnosis at ages 0-9, 10-19, 20-29, 30-39, 40-49, 50-59 and 60-69 years, 70, 62, 58, 53, 38, 19 and 33%, respectively, were allergic. For non-allergic asthma, the incidence rate was lowest in children and young adults (0.7/1000/year). It increased after middle age and was highest in older age groups (2.4/1000/year in 50-59 years old). Conclusions The incidence of allergic asthma is highest in early childhood and steadily decreases with advancing age, while the incidence of non-allergic asthma is low until it peaks in late adulthood. After approximately 40 years of age, most of the new cases of asthma are non-allergic.
  • Honkamäki, Jasmin; Piirilä, Päivi; Hisinger-Mölkänen, Hanna; Tuomisto, Leena E.; Andersen, Heidi; Huhtala, Heini; Sovijärvi, Anssi; Lindqvist, Ari; Backman, Helena; Lundbäck, Bo; Rönmark, Eva; Lehtimäki, Lauri; Pallasaho, Paula; Ilmarinen, Pinja; Kankaanranta, Hannu (2021)
    BACKGROUND: Child-onset asthma is known to remit with high probability, but remission in adult-onset asthma is seem-ingly less frequent. Reports of the association between remission and asthma age of onset up to late adulthood are scarce. OBJECTIVE: To evaluate the association between asthma remission, age at diagnosis and gender, and assess risk factors of nonremission. METHODS: In 2016, a random sample of 16,000 subjects aged 20 to 69 years from Helsinki and Western Finland were sent a FinEsS questionnaire. Physician-diagnosed asthma was catego-rized by age at diagnosis to early-(0-11 years), intermediate-(12-39 years), and late-diagnosed (40-69 years) asthma. Asthma remission was defined by not having had asthma symptoms and not having used asthma medication in the past 12 months. RESULTS: Totally, 8199 (51.5%) responded, and 879 reported physician-diagnosed asthma. Remission was most common in early-diagnosed (30.2%), followed by intermediate-diagnosed (17.9%), and least common in late-diagnosed asthma (5.0%) (P < .001), and the median times from diagnosis were 27, 18.5, and 10 years, respectively. In males, the corresponding remission rates were 36.7%, 20.0%, and 3.4%, and in females, 20.4%, 16.6%, and 5.9% (gender difference P < .001). In multivariable binary logistic regression analysis, signifi-cant risk factors of asthma nonremission were intermediate (odds ratio [OR] = 2.15, 95% confidence interval: 1.373.36) and late diagnosis (OR = 11.06, 4.82-25.37) compared with early diagnosis, chronic obstructive pulmonary disease (COPD) (OR = 5.56, 1.26-24.49), allergic rhinitis (OR = 2.28, 1.50-3.46), and family history of asthma (OR = 1.86, 1.22-2.85). Results were similar after excluding COPD. CONCLUSION: Remission was rare in adults diagnosed with asthma after age 40 years in both genders. Late-diagnosed asthma was the most significant independent risk factor for nonremission. (C) 2020 American Academy of Allergy, Asthma & Immunology
  • Heinla, Indrek; Åhlgren, Johanna; Vasar, Eero; Voikar, Vootele (2018)
    Developing reliable mouse models for social behaviour is challenging. Different tests have been proposed, but most of them consist of rather artificial confrontations of unfamiliar mice in novel arenas or are relying on social stress induced by aggressive conspecifics. Natural social interaction in home cage in laboratory has not been investigated well. IntelliCage is a fully automated home-cage system, where activity of the group-housed mice can be monitored along with various cognitive tasks. Here we report the behavioural profile of C57BL/6N (86) and BALB/c (BALB) female mice in IntelliCage when separated by strain, followed by monitoring of activity and formation of 'home-base' after mixing two strains. For that purpose, 3 cages were connected. Significant differences between the strains were established in baseline behaviour in conventional tests and in IntelliCage. The B6 mice showed reduced anxiety-like behaviour in open field and light-dark box, slightly enhanced exploratory activity in IntelliCage during initial adaptation and clearly distinct circadian activity. Mixing of two strains resulted in reduction of body weight and anhedonia in B6 mice. In addition, the B6 mice showed clear preference to previous home-cage, and formed a new home-base faster than BALB mice. In contrast, BALB mice showed enhanced activity and moving between the cages without showing any preference to previous home-cage. It could be argued that social challenge caused changes in both strains and different coping styles are responsible for behavioural manifestations. Altogether, this approach could be useful in modelling and validating mouse models for disorders with disturbed social behaviour.
  • Syrjänen, Leo; Valanne, Susanna; Kuuslahti, Marianne; Tuomela, Tea; Sriram, Ashwin; Sanz, Alberto; Jacobs, Howard T.; Rämet, Mika; Parkkila, Seppo (2015)
    Background: Carbonic anhydrases (CAs, EC 4.2.1.1) are ubiquitous enzymes that catalyze the reversible hydration reaction of carbon dioxide. CAs are present as six structurally divergent enzyme families: alpha, beta, gamma, delta, zeta and eta. beta-CAs have a wide distribution across different species including invertebrates. Previously, we showed that Drosophila melanogaster beta-CA is a highly active mitochondrial enzyme. In this study, we investigated the function of Drosophila beta-CA by silencing the expression of the beta-CA gene using UAS/GAL4-based RNA interference (RNAi) in Drosophila in vivo. Results: Crossing beta-CA RNAi lines over ubiquitous Actin driver flies did not produce any viable progeny, indicating that beta-CA expression is required for fly development. RNAi silencing of beta-CA ubiquitously in adult flies did not affect their survival rate or function of mitochondrial electron transport chain. Importantly, beta-CA RNAi led to impaired reproduction. All beta-CA knockdown females were sterile, and produced few or no eggs. Whole ovaries of knockdown females looked normal but upon cadherin staining, there was an apparent functional defect in migration of border cells, which are considered essential for normal fertilization. Conclusions: These results indicate that although Drosophila beta-CA is dispensable for survival of adult flies, it is essential for female fertility.
  • Morandin, Claire; Brendel, Volker P.; Sundstrom, Liselotte; Helantera, Heikki; Mikheyev, Alexander S. (2019)
    Social insects provide systems for studying epigenetic regulation of phenotypes, particularly with respect to differentiation of reproductive and worker castes, which typically arise from a common genetic background. The role of gene expression in caste specialization has been extensively studied, but the role of DNA methylation remains controversial. Here, we perform well replicated, integrated analyses of DNA methylation and gene expression in brains of an ant (Formica exsecta) with distinct female castes using traditional approaches (tests of differential methylation) combined with a novel approach (analysis of co-expression and co-methylation networks). We found differences in expression and methylation profiles between workers and queens at different life stages, as well as some overlap between DNA methylation and expression at the functional level. Large portions of the transcriptome and methylome are organized into "modules" of genes, some significantly associated with phenotypic traits of castes and developmental stages. Several gene co-expression modules are preserved in co-methylation networks, consistent with possible regulation of caste-specific gene expression by DNA methylation. Surprisingly, brain co-expression modules were highly preserved when compared with a previous study that examined whole-body co-expression patterns in 16 ant species, suggesting that these modules are evolutionarily conserved and for specific functions in various tissues. Altogether, these results suggest that DNA methylation participates in regulation of caste specialization and age-related physiological changes in social insects.
  • Holman, Luke; Helantera, Heikki; Trontti, Kalevi; Mikheyev, Alexander S. (2019)
    Queen pheromones are chemical signals that mediate reproductive division of labor in eusocial animals. Remarkably, queen pheromones are composed of identical or chemically similar compounds in some ants, wasps and bees, even though these taxa diverged > 150MYA and evolved queens and workers independently. Here, we measure the transcriptomic consequences of experimental exposure to queen pheromones in workers from two ant and two bee species (genera: Lasius, Apis, Bombus), and test whether they are similar across species. Queen pheromone exposure affected transcription and splicing at many loci. Many genes responded consistently in multiple species, and the set of pheromone-sensitive genes was enriched for functions relating to lipid biosynthesis and transport, olfaction, production of cuticle, oogenesis, and histone (de)acetylation. Pheromone-sensitive genes tend to be evolutionarily ancient, positively selected, peripheral in the gene coexpression network, hypomethylated, and caste-specific in their expression. Our results reveal how queen pheromones achieve their effects, and suggest that ants and bees use similar genetic modules to achieve reproductive division of labor.
  • van Zanten, Sophie E. M. Veldhuijzen; Baugh, Joshua; Chaney, Brooklyn; De Jongh, Dennis; Aliaga, Esther Sanchez; Barkhof, Frederik; Noltes, Johan; De Wolf, Ruben; Van Dijk, Jet; Cannarozzo, Antonio; Damen-Korbijn, Carin M.; Lieverst, Jan A.; Colditz, Niclas; Hoffmann, Marion; Warmuth-Metz, Monika; Bison, Brigitte; Jones, David T. W.; Sturm, Dominik; Gielen, Gerrit H.; Jones, Chris; Hulleman, Esther; Calmon, Raphael; Castel, David; Varlet, Pascale; Giraud, Geraldine; Slavc, Irene; Van Gool, Stefaan; Jacobs, Sandra; Jadrijevic-Cvrlje, Filip; Sumerauer, David; Nysom, Karsten; Pentikäinen, Virve; Kivivuori, Sanna-Maria; Leblond, Pierre; Entz-Werle, Natasha; von Bueren, Andre O.; Kattamis, Antonis; Hargrave, Darren R.; Hauser, Peter; Garami, Miklos; Thorarinsdottir, Halldora K.; Pears, Jane; Gandola, Lorenza; Rutkauskiene, Giedre; Janssens, Geert O.; Torsvik, Ingrid K.; Perek-Polnik, Marta; Gil-da-Costa, Maria J.; Zheludkova, Olga; Shats, Liudmila; SIOPE DIPG Network (2017)
    Diffuse intrinsic pontine glioma (DIPG) is a rare and deadly childhood malignancy. After 40 years of mostly single-center, often non-randomized trials with variable patient inclusions, there has been no improvement in survival. It is therefore time for international collaboration in DIPG research, to provide new hope for children, parents and medical professionals fighting DIPG. In a first step towards collaboration, in 2011, a network of biologists and clinicians working in the field of DIPG was established within the European Society for Paediatric Oncology (SIOPE) Brain Tumour Group: the SIOPE DIPG Network. By bringing together biomedical professionals and parents as patient representatives, several collaborative DIPG-related projects have been realized. With help from experts in the fields of information technology, and legal advisors, an international, web-based comprehensive database was developed, The SIOPE DIPG Registry and Imaging Repository, to centrally collect data of DIPG patients. As for April 2016, clinical data as well as MR-scans of 694 patients have been entered into the SIOPE DIPG Registry/Imaging Repository. The median progression free survival is 6.0 months (95% Confidence Interval (CI) 5.6-6.4 months) and the median overall survival is 11.0 months (95% CI 10.5-11.5 months). At two and five years post-diagnosis, 10 and 2% of patients are alive, respectively. The establishment of the SIOPE DIPG Network and SIOPE DIPG Registry means a paradigm shift towards collaborative research into DIPG. This is seen as an essential first step towards understanding the disease, improving care and (ultimately) cure for children with DIPG.
  • Leppaaho, Eemeli; Renvall, Hanna; Salmela, Elina; Kere, Juha; Salmelin, Riitta; Kaski, Samuel (2019)
    Brain structure and many brain functions are known to be genetically controlled, but direct links between neuroimaging measures and their underlying cellular-level determinants remain largely undiscovered. Here, we adopt a novel computational method for examining potential similarities in high-dimensional brain imaging data between siblings. We examine oscillatory brain activity measured with magnetoencephalography (MEG) in 201 healthy siblings and apply Bayesian reduced-rank regression to extract a low-dimensional representation of familial features in the participants' spectral power structure. Our results show that the structure of the overall spectral power at 1-90Hz is a highly conspicuous feature that not only relates siblings to each other but also has very high consistency within participants' own data, irrespective of the exact experimental state of the participant. The analysis is extended by seeking genetic associations for low-dimensional descriptions of the oscillatory brain activity. The observed variability in the MEG spectral power structure was associated with SDK1 (sidekick cell adhesion molecule 1) and suggestively with several other genes that function, for example, in brain development. The current results highlight the potential of sophisticated computational methods in combining molecular and neuroimaging levels for exploring brain functions, even for high-dimensional data limited to a few hundred participants.
  • Tani, Haruna; Mito, Takayuki; Velagapudi, Vidya; Ishikawa, Kaori; Umehara, Moe; Nakada, Kazuto; Suomalainen, Anu; Hayashi, Jun-Ichi (2019)
    In a previous study, we proposed that age-related mitochondrial respiration defects observed in elderly subjects are partially due to age-associated downregulation of nuclear-encoded genes, including serine hydroxymethyltransferase 2 (SHMT2), which is involved in mitochondrial one-carbon (1C) metabolism. This assertion is supported by evidence that the disruption of mouse Shmt2 induces mitochondrial respiration defects in mouse embryonic fibroblasts generated from Shmt2-knockout E13.5 embryos experiencing anaemia and lethality. Here, we elucidated the potential mechanisms by which the disruption of this gene induces mitochondrial respiration defects and embryonic anaemia using Shmt2-knockout E13.5 embryos. The livers but not the brains of Shmt2-knockout E13.5 embryos presented mitochondrial respiration defects and growth retardation. Metabolomic profiling revealed that Shmt2 deficiency induced foetal liver-specific downregulation of 1C-metabolic pathways that create taurine and nucleotides required for mitochondrial respiratory function and cell division, respectively, resulting in the manifestation of mitochondrial respiration defects and growth retardation. Given that foetal livers function to produce erythroblasts in mouse embryos, growth retardation in foetal livers directly induced depletion of erythroblasts. By contrast, mitochondrial respiration defects in foetal livers also induced depletion of erythroblasts as a consequence of the inhibition of erythroblast differentiation, resulting in the manifestation of anaemia in Shmt2-knockout E13.5 embryos.
  • Xu, Cheng-Jian; Soderhall, Cilla; Bustamante, Mariona; Baiz, Nour; Gruzieva, Olena; Gehring, Ulrike; Mason, Dan; Chatzi, Leda; Basterrechea, Mikel; Llop, Sabrina; Torrent, Maties; Forastiere, Francesco; Fantini, Maria Pia; Carlsen, Karin C. Lodrup; Haahtela, Tari; Morin, Andreanne; Kerkhof, Marjan; Merid, Simon Kebede; van Rijkom, Bianca; Jankipersadsing, Soesma A.; Bonder, Marc Jan; Ballereau, Stephane; Vermeulen, Cornelis J.; Aguirre-Gamboa, Raul; de Jongste, Johan C.; Smit, Henriette A.; Kumar, Ashish; Pershagen, Goran; Guerra, Stefano; Garcia-Aymerich, Judith; Greco, Dario; Reinius, Lovisa; McEachan, Rosemary R. C.; Azad, Raf; Hovland, Vegard; Mowinckel, Petter; Alenius, Harri; Fyhrquist, Nanna; Lemonnier, Nathanael; Pellet, Johann; Auffray, Charles; van der Vlies, Pieter; van Diemen, Cleo C.; Li, Yang; Wijmenga, Cisca; Netea, Mihai G.; Moffatt, Miriam F.; Cookson, William O. C. M.; Anto, Josep M.; Kere, Juha (2018)
    Background DNA methylation profiles associated with childhood asthma might provide novel insights into disease pathogenesis. We did an epigenome-wide association study to assess methylation profiles associated with childhood asthma. Methods We did a large-scale epigenome-wide association study (EWAS) within the Mechanisms of the Development of ALLergy (MeDALL) project. We examined epigenome-wide methylation using Illumina Infinium Human Methylation450 BeadChips (450K) in whole blood in 207 children with asthma and 610 controls at age 4-5 years, and 185 children with asthma and 546 controls at age 8 years using a cross-sectional case-control design. After identification of differentially methylated CpG sites in the discovery analysis, we did a validation study in children (4-16 years; 247 cases and 2949 controls) from six additional European cohorts and meta-analysed the results. We next investigated whether replicated CpG sites in cord blood predict later asthma in 1316 children. We subsequently investigated cell-type-specific methylation of the identified CpG sites in eosinophils and respiratory epithelial cells and their related gene-expression signatures. We studied cell-type specificity of the asthma association of the replicated CpG sites in 455 respiratory epithelial cell samples, collected by nasal brushing of 16-year-old children as well as in DNA isolated from blood eosinophils (16 with asthma, eight controls [age 2-56 years]) and compared this with whole-blood DNA samples of 74 individuals with asthma and 93 controls (age 1-79 years). Whole-blood transcriptional profiles associated with replicated CpG sites were annotated using RNA-seq data of subsets of peripheral blood mononuclear cells sorted by fluorescence-activated cell sorting. Findings 27 methylated CpG sites were identified in the discovery analysis. 14 of these CpG sites were replicated and passed genome-wide significance (p Interpretation Reduced whole-blood DNA methylation at 14 CpG sites acquired after birth was strongly associated with childhood asthma. These CpG sites and their associated transcriptional profiles indicate activation of eosinophils and cytotoxic T cells in childhood asthma. Our findings merit further investigations of the role of epigenetics in a clinical context.
  • Nikkola, Elina; Ko, Arthur; Alvarez, Marcus; Cantor, Rita M.; Garske, Kristina; Kim, Elliot; Gee, Stephanie; Rodriguez, Alejandra; Muxel, Reinhard; Matikainen, Niina; Soderlund, Sanni; Motazacker, Mahdi M.; Boren, Jan; Lamina, Claudia; Kronenberg, Florian; Schneider, Wolfgang J.; Palotie, Aarno; Laakso, Markku; Taskinen, Marja-Riitta; Pajukanta, Paivi (2017)
    Background and aims: Hypercholesterolemia confers susceptibility to cardiovascular disease (CVD). Both serum total cholesterol (TC) and LDL-cholesterol (LDL-C) exhibit a strong genetic component (heritability estimates 0.41-0.50). However, a large part of this heritability cannot be explained by the variants identified in recent extensive genome-wide association studies (GWAS) on lipids. Our aim was to find genetic causes leading to high LDL-C levels and ultimately CVD in a large Austrian family presenting with what appears to be autosomal dominant inheritance for familial hypercholesterolemia (FH). Methods: We utilized linkage analysis followed by whole-exome sequencing and genetic risk score analysis using an Austrian multi-generational family with various dyslipidemias, including elevated TC and LDL-C, and one family branch with elevated lipoprotein (a) (Lp(a)). Results: We did not find evidence for genome-wide significant linkage for LDL-C or apparent causative variants in the known FH genes rather, we discovered a particular family-specific combination of nine GWAS LDL-C SNPs (p = 0.02 by permutation), and putative less severe familial hypercholesterolemia mutations in the LDLR and APOB genes in a subset of the affected family members. Separately, high Lp(a) levels observed in one branch of the family were explained primarily by the LPA locus, including short (<23) Kringle IV repeats and rs3798220. Conclusions: Taken together, some forms of FH may be explained by family-specific combinations of LDL-C GWAS SNPs. (c) 2017 Elsevier B.V. All rights reserved.
  • Mahajan, Anubha; Taliun, Daniel; Thurner, Matthias; Robertson, Neil R.; Torres, Jason M.; Rayner, N. William; Payne, Anthony J.; Steinthorsdottir, Valgerdur; Scott, Robert A.; Grarup, Niels; Cook, James P.; Schmidt, Ellen M.; Wuttke, Matthias; Sarnowski, Chloe; Magill, Reedik; Nano, Jana; Gieger, Christian; Trompet, Stella; Lecoeur, Cecile; Preuss, Michael H.; Prins, Bram Peter; Guo, Xiuqing; Bielak, Lawrence F.; Below, Jennifer E.; Bowden, Donald W.; Chambers, John Campbell; Kim, Young Jin; Ng, Maggie C. Y.; Petty, Lauren E.; Sim, Xueling; Zhang, Weihua; Bennett, Amanda J.; Bork-Jensen, Jette; Brummett, Chad M.; Canouil, Mickael; Kardt, Kai-Uwe Ec; Fischer, Krista; Kardia, Sharon L. R.; Kronenberg, Florian; Lall, Kristi; Liu, Ching-Ti; Locke, Adam E.; Luan, Jian'an; Ntalla, Loanna; Nylander, Vibe; Schoenherr, Sebastian; Schurmann, Claudia; Yengo, Loic; Bottinger, Erwin P.; Brandslund, Ivan; Christensen, Cramer; Dedoussis, George; Florez, Jose C.; Ford, Ian; France, Oscar H.; Frayling, Timothy M.; Giedraitis, Vilmantas; Hackinger, Sophie; Hattersley, Andrew T.; Herder, Christian; Ikram, M. Arfan; Ingelsson, Martin; Jorgensen, Marit E.; Jorgensen, Torben; Kriebel, Jennifer; Kuusisto, Johanna; Ligthart, Symen; Lindgren, Cecilia M.; Linneberg, Allan; Lyssenko, Valeriya; Mamakou, Vasiliki; Meitinger, Thomas; Mohlke, Karen L.; Morris, Andrew D.; Nadkarni, Girish; Pankow, James S.; Peters, Annette; Sattar, Naveed; Stancakova, Alena; Strauch, Konstantin; Taylor, Kent D.; Thorand, Barbara; Thorleifsson, Gudmar; Thorsteinsdottir, Unnur; Tuomilehto, Jaakko; Witte, Daniel R.; Dupuis, Josee; Peyser, Patricia A.; Zeggini, Eleftheria; Loos, Ruth J. F.; Froguel, Philippe; Ingelsson, Erik; Lind, Lars; Groop, Leif; Laakso, Markku; Collins, Francis S.; Jukema, J. Wouter; Palmer, Colin N. A.; Grallert, Harald; Metspalu, Andres; Dehghan, Abbas; Koettgen, Anna; Abecasis, Goncalo R.; Meigs, James B.; Rotter, Jerome; Marchini, Jonathan; Pedersen, Oluf; Hansen, Torben; Langenberg, Claudia; Wareham, Nicholas J.; Stefansson, Kari; Gloyn, Anna L.; Morris, Andrew P.; Boehnke, Michael; McCarthy, Mark (2018)
    We expanded GWAS discovery for type 2 diabetes (T2D) by combining data from 898,130 European-descent individuals (9% cases), after imputation to high-density reference panels. With these data, we (i) extend the inventory of T2D-risk variants (243 loci,135 newly implicated in T2D predisposition, comprising 403 distinct association signals); (ii) enrich discovery of lower-frequency risk alleles (80 index variants with minor allele frequency 2); (iii) substantially improve fine-mapping of causal variants (at 51 signals, one variant accounted for >80% posterior probability of association (PPA)); (iv) extend fine-mapping through integration of tissue-specific epigenomic information (islet regulatory annotations extend the number of variants with PPA >80% to 73); (v) highlight validated therapeutic targets (18 genes with associations attributable to coding variants); and (vi) demonstrate enhanced potential for clinical translation (genome-wide chip heritability explains 18% of T2D risk; individuals in the extremes of a T2D polygenic risk score differ more than ninefold in prevalence).
  • Silventoinen, Karri; Maia, José; Jelenkovic, Aline; Pereira, Sara; Gouveia, Élvio; Antunes, António; Thomis, Martine; Lefevre, Johan; Kaprio, Jaakko; Freitas, Duarte (2021)
    Objectives To analyze the influence of genetic and environmental factors on the variation in somatotype, physical fitness, and their mutual associations. Methods Twins from 214 pairs (87 monozygotic) of the Autonomous Region of Madeira, Portugal, from 3 to 18 years of age (51% girls) were assessed in anthropometry and physical fitness tests. We estimated endomorphy, mesomorphy, and ectomorphy based on anthropometric measures and physical fitness using the Eurofit test battery. Two age categories were analyzed: children (3-11 years) and adolescents (12-18 years). Genetic and environmental variations were estimated using quantitative genetic twin modeling. Results No genetic sex differences were found, thus boys and girls were pooled in all genetic analyses. Heritability estimates were high for somatotype (a(2)= 0.80-0.93), physical fitness traits (a(2)= 0.67-0.83), and largely similar in children and adolescents. Positive correlations were found for ectomorphy with motor ability and cardiorespiratory endurance as well as for endomorphy and mesomorphy with muscular strength (r= 0.25-0.37). In contrast, negative associations were found for ectomorphy with muscular strength, as well as for endomorphy and mesomorphy with motor ability and cardiorespiratory endurance (-0.46 to -0.26). Twin modeling indicated that these associations were explained mostly by genetic factors in common to the two associated traits (84% or more). Conclusions Associations between somatotype and physical fitness tests are mainly explained by common genetic background in children and adolescents. Therefore, interventions in youth should consider that a child's performance in physical fitness tests partly reflects their inherited physique.
  • Fitak, Robert Rodgers; Mohandesan, Elmira; Corander, Jukka; Yadamsuren, Adiya; Chuluunbat, Battsetseg; Abdelhadi, Omer; Raziq, Abdul; Nagy, Peter; Walzer, Chris; Faye, Bernard; Burger, Pamela Anna (2020)
    Domestication begins with the selection of animals showing less fear of humans. In most domesticates, selection signals for tameness have been superimposed by intensive breeding for economical or other desirable traits. Old World camels, conversely, have maintained high genetic variation and lack secondary bottlenecks associated with breed development. By re-sequencing multiple genomes from dromedaries, Bactrian camels, and their endangered wild relatives, here we show that positive selection for candidate genes underlying traits collectively referred to as 'domestication syndrome' is consistent with neural crest deficiencies and altered thyroid hormone-based signaling. Comparing our results with other domestic species, we postulate that the core set of domestication genes is considerably smaller than the pan-domestication set - and overlapping genes are likely a result of chance and redundancy. These results, along with the extensive genomic resources provided, are an important contribution to understanding the evolutionary history of camels and the genomic features of their domestication. Robert R. Fitak et al. investigate the genetic basis for domestication in camels. They found that the positive selection of candidate domestication genes is consistent with neural crest deficiencies and altered thyroid hormone-based signaling. Their work provides insights to the evolutionary history of camels and genetics of domestication.
  • Vaattovaara, Aleksia Fanni Maria; Leppälä, Johanna Maria; Salojärvi, Jarkko Tapani; Wrzaczek, Michael Alois (2019)
    The use of draft genomes of different species and re-sequencing of accessions and populations are now a common tool for plant biology research. The de novo assembled draft genomes make it possible to identify pivotal divergence points in the plant lineage and provide an opportunity to investigate the genomic basis and timing of biological innovations by inferring orthologs between species. Furthermore, re-sequencing facilitates the mapping and subsequent molecular characterization of causative loci for traits including plant stress tolerance or development. In both cases high quality gene annotation, the identification of protein-coding regions, gene promoters and 5’ and 3’ untranslated regions, is critical for investigation of gene function. Annotations are constantly improving but automated gene annotations still require manual curation and experimental validation. This is particularly important for genes with large introns, genes located in regions rich with transposable elements or repeats, large gene families and segmentally duplicated genes. In this opinion paper we highlight the impact of annotation quality on evolutionary analyses, genome-wide association studies and the identification of orthologous genes in plants. Furthermore, we predict that incorporating the accurate information from manual curation into databases will dramatically improve the performance of automated gene predictors.
  • 23 Me Res Team; Syst Genomics Parkinson's Dis; Int Parkinson's Dis Genomics; Nalls, Mike A.; Blauwendraat, Cornelis; Tienari, Pentti (2019)
    Background Genome-wide association studies (GWAS) in Parkinson's disease have increased the scope of biological knowledge about the disease over the past decade. We aimed to use the largest aggregate of GWAS data to identify novel risk loci and gain further insight into the causes of Parkinson's disease. Methods We did a meta-analysis of 17 datasets from Parkinson's disease GWAS available from European ancestry samples to nominate novel loci for disease risk. These datasets incorporated all available data. We then used these data to estimate heritable risk and develop predictive models of this heritability. We also used large gene expression and methylation resources to examine possible functional consequences as well as tissue, cell type, and biological pathway enrichments for the identified risk factors. Additionally, we examined shared genetic risk between Parkinson's disease and other phenotypes of interest via genetic correlations followed by Mendelian randomisation. Findings Between Oct 1, 2017, and Aug 9, 2018, we analysed 7.8 million single nucleotide polymorphisms in 37688 cases, 18 618 UK Biobank proxy-cases (ie, individuals who do not have Parkinson's disease but have a first degree relative that does), and 1.4 million controls. We identified 90 independent genome-wide significant risk signals across 78 genomic regions, including 38 novel independent risk signals in 37 loci. These 90 variants explained 16-36% of the heritable risk of Parkinson's disease depending on prevalence. Integrating methylation and expression data within a Mendelian randomisation framework identified putatively associated genes at 70 risk signals underlying GWAS loci for follow-up functional studies. Tissue-specific expression enrichment analyses suggested Parkinson's disease loci were heavily brain-enriched, with specific neuronal cell types being implicated from single cell data. We found significant genetic correlations with brain volumes (false discovery rate-adjusted p=0 .0035 for intracranial volume, p=0.024 for putamen volume), smoking status (p=0.024), and educational attainment (p=0.038). Mendelian randomisation between cognitive performance and Parkinson's disease risk showed a robust association (p=8.00 x10 -7). Interpretation These data provide the most comprehensive survey of genetic risk within Parkinson's disease to date, to the best of our knowledge, by revealing many additional Parkinson's disease risk loci, providing a biological context for these risk factors, and showing that a considerable genetic component of this disease remains unidentified. These associations derived from European ancestry datasets will need to be followed-up with more diverse data. Copyright (C) 2019 Elsevier Ltd. All rights reserved.
  • Hagihara, Hideo; Fujita, Masayo; Umemori, Juzoh; Hashimoto, Makoto; Miyakawa, Tsuyoshi (2018)
    AIM: Maturation abnormalities of the brain cells have been suggested in several neuropsychiatric disorders, including schizophrenia, bipolar disorder, autism spectrum disorders, and epilepsy. In this study, we examined the expression patterns of neuronal maturation markers in the brain of a mouse model of dementia with Lewy body-linked mutant β-synuclein (βS), especially in the hippocampus, to explore whether such brain abnormalities occur in neurodegenerative disorders as well. METHODS: Quantitative PCR (qPCR) and immunohistochemical analyses were performed using the hippocampus of 14-month-old P123H βS transgenic (Tg) mice to evaluate the expression of molecular markers for maturation of dentate granule cells. RESULTS: Based on qPCR results, expression of Tdo2 and Dsp (markers of mature granule cells) was decreased and that of Drd1a (a marker of immature granule cells) was increased in the hippocampus of P123H βS Tg mice compared to that in wild-type controls. Immunohistochemical analysis revealed decreased expression of mature granule cell markers Calb1 and Gria1, along with increased expression of the microglial marker Iba1, in the hippocampal dentate gyrus region of P123H βS Tg mice. P123H βS Tg mice exhibited immature-like neuronal molecular expression patterns and microgliosis in the hippocampus. Pseudo-immaturity of dentate granule cells, associated with neuroinflammation, may be a shared endophenotype in the brains of at least a subgroup of patients with neuropsychiatric disorders and neurodegenerative diseases.
  • Westberg, Anna P.; Salonen, Minna K.; von Bonsdorff, Mikaela; Osmond, Clive; Kajantie, Eero; Eriksson, Johan G. (2018)
  • Ganel, Liron; Chen, Lei; Christ, Ryan; Vangipurapu, Jagadish; Young, Erica; Das, Indraniel; Kanchi, Krishna; Larson, David; Regier, Allison; Abel, Haley; Kang, Chul Joo; Scott, Alexandra; Havulinna, Aki; Chiang, Charleston W. K.; Service, Susan; Freimer, Nelson; Palotie, Aarno; Ripatti, Samuli; Kuusisto, Johanna; Boehnke, Michael; Laakso, Markku; Locke, Adam; Stitziel, Nathan O.; Hall, Ira M. (2021)
    Background Mitochondrial genome copy number (MT-CN) varies among humans and across tissues and is highly heritable, but its causes and consequences are not well understood. When measured by bulk DNA sequencing in blood, MT-CN may reflect a combination of the number of mitochondria per cell and cell-type composition. Here, we studied MT-CN variation in blood-derived DNA from 19184 Finnish individuals using a combination of genome (N = 4163) and exome sequencing (N = 19034) data as well as imputed genotypes (N = 17718). Results We identified two loci significantly associated with MT-CN variation: a common variant at the MYB-HBS1L locus (P = 1.6 x 10(-8)), which has previously been associated with numerous hematological parameters; and a burden of rare variants in the TMBIM1 gene (P = 3.0 x 10(-8)), which has been reported to protect against non-alcoholic fatty liver disease. We also found that MT-CN is strongly associated with insulin levels (P = 2.0 x 10(-21)) and other metabolic syndrome (metS)-related traits. Using a Mendelian randomization framework, we show evidence that MT-CN measured in blood is causally related to insulin levels. We then applied an MT-CN polygenic risk score (PRS) derived from Finnish data to the UK Biobank, where the association between the PRS and metS traits was replicated. Adjusting for cell counts largely eliminated these signals, suggesting that MT-CN affects metS via cell-type composition. Conclusion These results suggest that measurements of MT-CN in blood-derived DNA partially reflect differences in cell-type composition and that these differences are causally linked to insulin and related traits.