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Ledesma-Colunga MG, Passin V, Vujic Spasic M, Hofbauer LC, Baschant U, Rauner M. Comparison of the effects of high dietary iron levels on bone microarchitecture responses in the mouse strains 129/Sv and C57BL/6J. Sci Rep 2024; 14:4887. [PMID: 38418857 PMCID: PMC10902348 DOI: 10.1038/s41598-024-55303-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 02/22/2024] [Indexed: 03/02/2024] Open
Abstract
Iron is an essential nutrient for all living organisms. Both iron deficiency and excess can be harmful. Bone, a highly metabolic active organ, is particularly sensitive to fluctuations in iron levels. In this study, we investigated the effects of dietary iron overload on bone homeostasis with a specific focus on two frequently utilized mouse strains: 129/Sv and C57BL/6J. Our findings revealed that after 6 weeks on an iron-rich diet, 129/Sv mice exhibited a decrease in trabecular and cortical bone density in both vertebral and femoral bones, which was linked to reduced bone turnover. In contrast, there was no evidence of bone changes associated with iron overload in age-matched C57BL/6J mice. Interestingly, 129/Sv mice exposed to an iron-rich diet during their prenatal development were protected from iron-induced bone loss, suggesting the presence of potential adaptive mechanisms. Overall, our study underscores the critical role of genetic background in modulating the effects of iron overload on bone health. This should be considered when studying effects of iron on bone.
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Affiliation(s)
- Maria G Ledesma-Colunga
- Department of Medicine III & Center for Healthy Aging, Medical Faculty and University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - Vanessa Passin
- Department of Medicine III & Center for Healthy Aging, Medical Faculty and University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - Maja Vujic Spasic
- Institute of Comparative Molecular Endocrinology, Ulm University, Ulm, Germany
| | - Lorenz C Hofbauer
- Department of Medicine III & Center for Healthy Aging, Medical Faculty and University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - Ulrike Baschant
- Department of Medicine III & Center for Healthy Aging, Medical Faculty and University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - Martina Rauner
- Department of Medicine III & Center for Healthy Aging, Medical Faculty and University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden, Germany.
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2
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Moksnes MR, Graham SE, Wu KH, Hansen AF, Gagliano Taliun SA, Zhou W, Thorstensen K, Fritsche LG, Gill D, Mason A, Cucca F, Schlessinger D, Abecasis GR, Burgess S, Åsvold BO, Nielsen JB, Hveem K, Willer CJ, Brumpton BM. Genome-wide meta-analysis of iron status biomarkers and the effect of iron on all-cause mortality in HUNT. Commun Biol 2022; 5:591. [PMID: 35710628 PMCID: PMC9203493 DOI: 10.1038/s42003-022-03529-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 05/24/2022] [Indexed: 01/19/2023] Open
Abstract
Iron is essential for many biological processes, but iron levels must be tightly regulated to avoid harmful effects of both iron deficiency and overload. Here, we perform genome-wide association studies on four iron-related biomarkers (serum iron, serum ferritin, transferrin saturation, total iron-binding capacity) in the Trøndelag Health Study (HUNT), the Michigan Genomics Initiative (MGI), and the SardiNIA study, followed by their meta-analysis with publicly available summary statistics, analyzing up to 257,953 individuals. We identify 123 genetic loci associated with iron traits. Among 19 novel protein-altering variants, we observe a rare missense variant (rs367731784) in HUNT, which suggests a role for DNAJC13 in transferrin recycling. We further validate recently published results using genetic risk scores for each biomarker in HUNT (6% variance in serum iron explained) and present linear and non-linear Mendelian randomization analyses of the traits on all-cause mortality. We find evidence of a harmful effect of increased serum iron and transferrin saturation in linear analyses that estimate population-averaged effects. However, there was weak evidence of a protective effect of increasing serum iron at the very low end of its distribution. Our findings contribute to our understanding of the genes affecting iron status and its consequences on human health.
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Affiliation(s)
- Marta R Moksnes
- K.G. Jebsen Center for Genetic Epidemiology, Department of Public Health and Nursing, NTNU - Norwegian University of Science and Technology, Trondheim, Norway.
| | - Sarah E Graham
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Kuan-Han Wu
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Ailin Falkmo Hansen
- K.G. Jebsen Center for Genetic Epidemiology, Department of Public Health and Nursing, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
| | - Sarah A Gagliano Taliun
- Department of Medicine and Department of Neurosciences, Université de Montréal, Montréal, QC, Canada
- Montréal Heart Institute, Montréal, QC, Canada
| | - Wei Zhou
- Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Ketil Thorstensen
- Department of Clinical Chemistry, St. Olavs hospital Trondheim University Hospital, Trondheim, Norway
| | - Lars G Fritsche
- Department of Biostatistics, University of Michigan School of Public Health, Ann Arbor, MI, USA
- Center for Statistical Genetics, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Dipender Gill
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK
- Clinical Pharmacology and Therapeutics Section, Institute for Infection and Immunity, St George's, University of London, London, UK
- Clinical Pharmacology Group, Pharmacy and Medicines Directorate, St George's University Hospitals NHS Foundation Trust, London, UK
- Novo Nordisk Research Centre Oxford, Old Road Campus, Oxford, UK
| | - Amy Mason
- British Heart Foundation Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
| | - Francesco Cucca
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche (CNR), Cagliari, Italy
- Dipartimento di Scienze Biomediche, Università degli Studi di Sassari, Sassari, Italy
| | - David Schlessinger
- Laboratory of Genetics, National Institute on Aging, US National Institutes of Health, Baltimore, MD, USA
| | - Gonçalo R Abecasis
- Center for Statistical Genetics, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Stephen Burgess
- British Heart Foundation Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
- Medical Research Council Biostatistics Unit, University of Cambridge, Cambridge, UK
| | - Bjørn Olav Åsvold
- K.G. Jebsen Center for Genetic Epidemiology, Department of Public Health and Nursing, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
- Department of Endocrinology, Clinic of Medicine, St. Olavs hospital Trondheim University Hospital, Trondheim, Norway
- HUNT Research Centre, Department of Public Health and Nursing, NTNU - Norwegian University of Science and Technology, Levanger, Norway
| | - Jonas B Nielsen
- K.G. Jebsen Center for Genetic Epidemiology, Department of Public Health and Nursing, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
- Department of Epidemiology Research, Statens Serum Institute, Copenhagen, Denmark
- Department of Cardiology, Copenhagen University Hospital, Copenhagen, Denmark
| | - Kristian Hveem
- K.G. Jebsen Center for Genetic Epidemiology, Department of Public Health and Nursing, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
- HUNT Research Centre, Department of Public Health and Nursing, NTNU - Norwegian University of Science and Technology, Levanger, Norway
| | - Cristen J Willer
- K.G. Jebsen Center for Genetic Epidemiology, Department of Public Health and Nursing, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
- Montréal Heart Institute, Montréal, QC, Canada
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Ben M Brumpton
- K.G. Jebsen Center for Genetic Epidemiology, Department of Public Health and Nursing, NTNU - Norwegian University of Science and Technology, Trondheim, Norway.
- HUNT Research Centre, Department of Public Health and Nursing, NTNU - Norwegian University of Science and Technology, Levanger, Norway.
- Clinic of Medicine, St. Olavs hospital Trondheim University Hospital, Trondheim, Norway.
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3
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Iglesias-Vázquez L, Arija V, Aranda N, Aglago EK, Cross AJ, Schulze MB, Quintana Pacheco D, Kühn T, Weiderpass E, Tumino R, Redondo-Sánchez D, de Magistris MS, Palli D, Ardanaz E, Laouali N, Sonestedt E, Drake I, Rizzolo L, Santiuste C, Sacerdote C, Quirós R, Amiano P, Agudo A, Jakszyn P. Factors associated with serum ferritin levels and iron excess: results from the EPIC-EurGast study. Eur J Nutr 2022; 61:101-114. [PMID: 34213605 DOI: 10.1007/s00394-021-02625-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 06/24/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE Excess iron is involved in the development of non-communicable diseases such as cancer, type 2 diabetes and cardiovascular conditions. We aimed to describe the prevalence of excess iron and its determinants in healthy European adults. METHODS Sociodemographic, lifestyle, iron status, dietary information, and HFE genotyping were obtained from controls from the nested case-control study EPIC-EurGast study. High sensitivity C-reactive protein (hsCRP) was measured to address possible systemic inflammation. Descriptive and multivariate analyses were used to assess iron status and its determinants. RESULTS Out of the 828 participants (median age: 58.7 years), 43% were females. Median serum ferritin and prevalence of excess iron were 143.7 µg/L and 35.2% in males, respectively, and 77 µg/L and 20% in females, both increasing with latitude across Europe. Prevalence of HFE C282Y mutation was significantly higher in Northern and Central Europe (~ 11%) than in the South (5%). Overweight/obesity, age, and daily alcohol and heme iron intake were independent determinants for iron status, with sex differences even after excluding participants with hsCRP > 5 mg/L. Obese males showed a greater consumption of alcohol, total and red meat, and heme iron, compared with those normal weight. CONCLUSION Obesity, higher alcohol and heme iron consumption were the main risk factors for excess iron in males while only age was associated with iron overload in females. Weight control and promoting healthy lifestyle may help prevent iron overload, especially in obese people. Further research is needed to clarify determinants of excess iron in the healthy adult population, helping to reduce the associated comorbidities.
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Affiliation(s)
- Lucía Iglesias-Vázquez
- Research group of Nutrition and Mental Health (NUTRISAM), Unit of Nutrition and Public Health, Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili (URV), Tarragona, Spain
- Institut d'Investigació Sanitària Pere Virgili (IISPV), Reus, Spain
| | - Victoria Arija
- Research group of Nutrition and Mental Health (NUTRISAM), Unit of Nutrition and Public Health, Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili (URV), Tarragona, Spain.
- Institut d'Investigació Sanitària Pere Virgili (IISPV), Reus, Spain.
- Institut d'investigació en Atenció Primària (IDIAP) Jordi Gol, Institut Català de la Salut (ICS), Barcelona, Spain.
| | - Núria Aranda
- Research group of Nutrition and Mental Health (NUTRISAM), Unit of Nutrition and Public Health, Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili (URV), Tarragona, Spain
- Institut d'Investigació Sanitària Pere Virgili (IISPV), Reus, Spain
| | - Elom K Aglago
- International Agency for Research on Cancer (IARC), Lyon, France
| | - Amanda J Cross
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK
| | - Matthias B Schulze
- Department of Molecular Epidemiology, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
- Institute of Nutritional Science, University of Potsdam, Nuthetal, Germany
| | | | - Tilman Kühn
- Division of Cancer Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | | | - Rosario Tumino
- Cancer Registry and Histopathology Department, Provincial Health Authority (ASP 7) Ragusa, Ragusa, Italy
| | - Daniel Redondo-Sánchez
- Escuela Andaluza de Salud Pública (EASP), Granada, Spain
- Instituto de Investigación Biosanitaria ibs.GRANADA, Granada, Spain
- Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | | | - Domenico Palli
- Cancer Risk Factors and Life-Style Epidemiology Unit Institute for Cancer Research, Prevention and Clinical Network (ISPRO), Villa delle Rose, Florence, Italy
| | - Eva Ardanaz
- Navarra Public Health Institute, Pamplona, Spain
- IdiSNA, Navarra Institute for Health Research, Pamplona, Spain
- CIBER Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Nasser Laouali
- Paris-Saclay University, UVSQ, University Paris-Sud, Inserm, Gustave Roussy, "Exposome and Heredity" Team, CESP, 94805, Villejuif, France
| | - Emily Sonestedt
- Nutritional Epidemiology, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
| | - Isabel Drake
- Nutritional Epidemiology, Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
| | - Lucía Rizzolo
- Unit of Nutrition and Cancer, Catalan Institute of Oncology - ICO, Nutrition and Cancer Group, Bellvitge Biomedical Research Institute -(IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Carmen Santiuste
- CIBER Epidemiology and Public Health (CIBERESP), Madrid, Spain
- Department of Epidemiology, Murcia Regional Health Council, IMIB-Arrixaca, Murcia, Spain
| | - Carlotta Sacerdote
- Unit of Cancer Epidemiology, Città Della Salute e Della Scienza University-Hospital, Via Santena 7, 10126, Turin, Italy
| | - Ramón Quirós
- EPIC Asturias, Public Health Directorate, Asturias, Spain
| | - Pilar Amiano
- CIBER Epidemiology and Public Health (CIBERESP), Madrid, Spain
- Public Health Division of Gipuzkoa, BioDonostia Research Institute, Donostia-San Sebastian, Spain
| | - Antonio Agudo
- Unit of Nutrition and Cancer, Catalan Institute of Oncology - ICO, Nutrition and Cancer Group, Bellvitge Biomedical Research Institute -(IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Paula Jakszyn
- Unit of Nutrition and Cancer, Catalan Institute of Oncology - ICO, Nutrition and Cancer Group, Bellvitge Biomedical Research Institute -(IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain.
- Blanquerna School of Health Sciences, Ramon Llull University, Barcelona, Spain.
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4
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Liu PJ, Yao A, Chen XY, Liu Y, Ma L, Hou YX. Associations of TMPRSS6 Polymorphisms with Gestational Diabetes Mellitus in Chinese Han Pregnant Women: a Preliminary Cohort Study. Biol Trace Elem Res 2021; 199:473-481. [PMID: 32363518 DOI: 10.1007/s12011-020-02169-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 04/24/2020] [Indexed: 01/19/2023]
Abstract
Body iron status is likely to be associated with type 2 diabetes (T2DM) and gestational diabetes mellitus (GDM); transmembrane protease serine 6 (TMPRSS6) polymorphisms may be associated with T2DM risk through their effects on body iron status. However, it remains unknown whether the TMPRSS6 single nucleotide polymorphisms (SNPs) affect the risk of GDM development. We aimed to determine whether the TMPRSS6 SNPs rs855791 (V736A) and rs4820268 (D521D) are associated with the risk of GDM in pregnant women. The two SNPs in TMPRSS6 gene were genotyped and examined for their associations with body iron status and GDM risk in 398 unrelated Chinese Han pregnant women. The 2 TMPRSS6 SNPs rs855791 and rs4820268 were both significantly associated with serum iron and transferrin saturation (P < 0.01 for all) rather than ferritin. After adjustment for covariates, the C allele of rs4820268 was nominally and significantly associated with an increased risk of GDM (OR = 2.531; 95%CI = 1.044-6.136, P = 0.040); when concentrations of ferritin were further adjusted, the association was still significant (OR = 2.528; 95%CI = 1.043-6.126, P = 0.040). There was a significant trend (P = 0.065) in the association between the T allele of rs855791 and an increased GDM risk in this study population. The 2 TMPRSS6 SNPs rs855791 and rs4820268 were both significantly associated with serum iron and transferrin saturation, and TMPRSS6 variants might be associated with the risk of GDM. Furthermore, the effects of TMPRSS6 SNPs on the risk of GDM may not be completely explained by the mediation of body iron status. Further studies are warranted.
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Affiliation(s)
- Peng Ju Liu
- The Department of Clinical Nutrition, Peking Union Medical College Hospital, China Academic Medical Science and Peking Union Medical College, Beijing, People's Republic of China
| | - Aimin Yao
- The Department of Gynaecology and Obstetrics, Shunyi Women's and Children's Hospital, Beijing, People's Republic of China
| | - Xiao Yan Chen
- The Department of Gynaecology and Obstetrics, Quanzhou Maternal and Child Health Hospital, Quanzhou, Fujian, People's Republic of China
| | - Yanping Liu
- The Department of Clinical Nutrition, Peking Union Medical College Hospital, China Academic Medical Science and Peking Union Medical College, Beijing, People's Republic of China.
| | - Liangkun Ma
- Department of Gynaecology and Obstetrics, Peking Union Medical College Hospital, China Academic Medical Science and Peking Union Medical College, Beijing, People's Republic of China
| | - Yi Xuan Hou
- School of Nursing, Peking Union Medical College, Beijing, People's Republic of China
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5
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Jallow MW, Cerami C, Clark TG, Prentice AM, Campino S. Differences in the frequency of genetic variants associated with iron imbalance among global populations. PLoS One 2020; 15:e0235141. [PMID: 32609760 PMCID: PMC7329092 DOI: 10.1371/journal.pone.0235141] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 06/09/2020] [Indexed: 02/08/2023] Open
Abstract
Iron deficiency anaemia is a major health problem affecting approximately 1.2 billion people worldwide. Young children, women of reproductive age and pregnant women living in sub-Saharan Africa are the most vulnerable. It is estimated that iron deficiency accounts for half of anaemia cases. Apart from nutritional deficiency, infection, inflammation and genetic factors are the major drivers of anaemia. However, the role of genetic risk factors has not been thoroughly investigated. This is particularly relevant in African populations, as they carry high genetic diversity and have a high prevalence of anaemia. Multiple genetic variations in iron regulatory genes have been linked to impaired iron status. Here we conducted a literature review to identify genetic variants associated with iron imbalance among global populations. We compare their allele frequencies and risk scores and we investigated population-specific selection among populations of varying geographic origin using data from the Keneba Biobank representing individuals in rural Gambia and the 1000 Genomes Project. We identified a significant lack of data on the genetic determinants of iron status in sub-Saharan Africa. Most of the studies on genetic determinants of iron status have been conducted in Europeans. Also, we identified population differences in allele frequencies in candidate putative genetic risk factors. Given the disproportionately high genetic diversity in African populations coupled with their high prevalence of iron deficiency, there is need to investigate the genetic influences of low iron status in Sub-Saharan Africa. The resulting insights may inform the future implementation of iron intervention strategies.
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Affiliation(s)
- Momodou W. Jallow
- Nutrition Theme, MRC Unit The Gambia at London School of Hygiene & Tropical Medicine, Banjul, The Gambia
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- * E-mail: (SC); (MWJ)
| | - Carla Cerami
- Nutrition Theme, MRC Unit The Gambia at London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Taane G. Clark
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Andrew M. Prentice
- Nutrition Theme, MRC Unit The Gambia at London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Susana Campino
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- * E-mail: (SC); (MWJ)
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6
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Genetics of Biochemical Phenotypes. Twin Res Hum Genet 2020; 23:77-79. [PMID: 32482194 DOI: 10.1017/thg.2020.26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Biomarkers diagnose, predict or assess the risk of disease, and studies of the effects of genetic variation on biomarker phenotypes in the general population complement studies on patients diagnosed with disease. This paper traces the evolution of studies on biomarker genetics over the past 40 years through examples drawn from the work of Professor Martin and his colleagues.
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7
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Sumi MP, Guru SA, Sahu S, Khan B, Mp G, Saxena A. “Role of HFE gene in coronary artery disease” – A study from India. CLINICAL EPIDEMIOLOGY AND GLOBAL HEALTH 2020. [DOI: 10.1016/j.cegh.2019.10.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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8
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Adams PC, Barton JC. Iron overload and cirrhosis in referred HFE p.C282Y homozygotes with normal transferrin saturation and elevated serum ferritin. CANADIAN LIVER JOURNAL 2020. [DOI: 10.3138/canlivj-2019-0013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Background: Elevated transferrin saturation (TS) is an imperfect test to identify adults with high-iron gene ( HFE) p.C282Y homozygosity or elevated hepatic iron concentration. Methods: We analyzed observations of non-screening, previously untreated p.C282Y homozygotes who presented with both normal TS (<50% men, <45% women) and elevated serum ferritin (SF; men, >300 µg/L; women, >200 µg/L). Iron overload was defined as hepatocyte iron grade 3 or 4, liver iron >35 µmol/g dry weight, or iron removed by phlebotomy ≥3 g. Cirrhosis was defined as regenerating nodules of hepatocytes surrounded by bands of fibrous connective tissue. Results: Among 917 referred p.C282Y homozygotes, 58 (33 men, 25 women) had normal TS and elevated SF (6.3% [95% CI 4.9% to 8.1%]). Of 58 patients, 14 (24.1%) underwent liver biopsy; all 14 had hepatocyte iron grade 3 or 4. Fatty infiltration was reported in 6 of 14 liver biopsies (42.9%). Liver iron was >35 µmol/g dry weight in 7 of 8 patients tested (87.5%). Iron removed by phlebotomy was ≥3 g in 75.0% (15/20) of men and 62.5% (5/8) of women. Of 58 patients, 3 (5.2%) had iron overload and cirrhosis; each also had a proven or possible non-iron liver condition that may have acted in synergy with liver iron to increase cirrhosis risk. Conclusions: Iron overload is common in non-screening, previously untreated HFE p.C282Y homozygotes with normal TS and elevated SF. Among our sample, 5.2% had cirrhosis. Clinicians should not assume that patients with normal TS and elevated SF do not have HFE p.C282Y homozygosity, iron overload, or cirrhosis.
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Affiliation(s)
- Paul C Adams
- Department of Medicine, University Hospital, Western University, London, Ontario
| | - James C Barton
- Southern Iron Disorders Center, Birmingham, Alabama, USA
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
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9
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Adams PC, Barton JC. Iron overload and cirrhosis in referred HFE p.C282Y homozygotes with normal transferrin saturation and elevated serum ferritin. CANADIAN LIVER JOURNAL 2020; 3:188-193. [DOI: 10.3138/canlivj.2019-0013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 08/04/2019] [Indexed: 01/10/2023]
Abstract
Background: Elevated transferrin saturation (TS) is an imperfect test to identify adults with high-iron gene ( HFE) p.C282Y homozygosity or elevated hepatic iron concentration. Methods: We analyzed observations of non-screening, previously untreated p.C282Y homozygotes who presented with both normal TS (<50% men, <45% women) and elevated serum ferritin (SF; men, >300 µg/L; women, >200 µg/L). Iron overload was defined as hepatocyte iron grade 3 or 4, liver iron >35 µmol/g dry weight, or iron removed by phlebotomy ≥3 g. Cirrhosis was defined as regenerating nodules of hepatocytes surrounded by bands of fibrous connective tissue. Results: Among 917 referred p.C282Y homozygotes, 58 (33 men, 25 women) had normal TS and elevated SF (6.3% [95% CI 4.9% to 8.1%]). Of 58 patients, 14 (24.1%) underwent liver biopsy; all 14 had hepatocyte iron grade 3 or 4. Fatty infiltration was reported in 6 of 14 liver biopsies (42.9%). Liver iron was >35 µmol/g dry weight in 7 of 8 patients tested (87.5%). Iron removed by phlebotomy was ≥3 g in 75.0% (15/20) of men and 62.5% (5/8) of women. Of 58 patients, 3 (5.2%) had iron overload and cirrhosis; each also had a proven or possible non-iron liver condition that may have acted in synergy with liver iron to increase cirrhosis risk. Conclusions: Iron overload is common in non-screening, previously untreated HFE p.C282Y homozygotes with normal TS and elevated SF. Among our sample, 5.2% had cirrhosis. Clinicians should not assume that patients with normal TS and elevated SF do not have HFE p.C282Y homozygosity, iron overload, or cirrhosis.
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Affiliation(s)
- Paul C Adams
- Department of Medicine, University Hospital, Western University, London, Ontario
| | - James C Barton
- Southern Iron Disorders Center, Birmingham, Alabama, USA
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
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10
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Walther B, Lett AM, Bordoni A, Tomás‐Cobos L, Nieto JA, Dupont D, Danesi F, Shahar DR, Echaniz A, Re R, Fernandez AS, Deglaire A, Gille D, Schmid A, Vergères G. GutSelf: Interindividual Variability in the Processing of Dietary Compounds by the Human Gastrointestinal Tract. Mol Nutr Food Res 2019; 63:e1900677. [PMID: 31483113 PMCID: PMC6900003 DOI: 10.1002/mnfr.201900677] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 07/25/2019] [Indexed: 12/19/2022]
Abstract
Nutritional research is currently entering the field of personalized nutrition, to a large extent driven by major technological breakthroughs in analytical sciences and biocomputing. An efficient launching of the personalized approach depends on the ability of researchers to comprehensively monitor and characterize interindividual variability in the activity of the human gastrointestinal tract. This information is currently not available in such a form. This review therefore aims at identifying and discussing published data, providing evidence on interindividual variability in the processing of the major nutrients, i.e., protein, fat, carbohydrates, vitamins, and minerals, along the gastrointestinal tract, including oral processing, intestinal digestion, and absorption. Although interindividual variability is not a primary endpoint of most studies identified, a significant number of publications provides a wealth of information on this topic for each category of nutrients. This knowledge remains fragmented, however, and understanding the clinical relevance of most of the interindividual responses to food ingestion described in this review remains unclear. In that regard, this review has identified a gap and sets the base for future research addressing the issue of the interindividual variability in the response of the human organism to the ingestion of foods.
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Affiliation(s)
- Barbara Walther
- AgroscopeFederal Department of Economic AffairsEducation and Research EAER3003BerneSwitzerland
| | - Aaron M. Lett
- Section for Nutrition ResearchDepartment of MedicineImperial College LondonLondonUK
| | - Alessandra Bordoni
- Department of Agri‐Food Sciences and TechnologiesUniversity of Bologna47521CesenaItaly
| | | | | | - Didier Dupont
- UMR 1253Science et Technologie du Lait et de l'ŒufINRA35000RennesFrance
| | - Francesca Danesi
- Department of Agri‐Food Sciences and TechnologiesUniversity of Bologna47521CesenaItaly
| | - Danit R. Shahar
- Department of Public HealthThe S. Daniel Abraham International Center for Health and NutritionBen‐Gurion University of the Negev84105Beer‐ShevaIsrael
| | - Ana Echaniz
- Cambridge Food Science LtdCB23 5ABCambridgeUK
| | - Roberta Re
- Cambridge Food Science LtdCB23 5ABCambridgeUK
| | | | - Amélie Deglaire
- UMR 1253Science et Technologie du Lait et de l'ŒufINRA35000RennesFrance
| | - Doreen Gille
- AgroscopeFederal Department of Economic AffairsEducation and Research EAER3003BerneSwitzerland
| | - Alexandra Schmid
- AgroscopeFederal Department of Economic AffairsEducation and Research EAER3003BerneSwitzerland
| | - Guy Vergères
- AgroscopeFederal Department of Economic AffairsEducation and Research EAER3003BerneSwitzerland
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A critical evaluation of results from genome-wide association studies of micronutrient status and their utility in the practice of precision nutrition. Br J Nutr 2019; 122:121-130. [DOI: 10.1017/s0007114519001119] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
AbstractRapid advances in ‘omics’ technologies have paved the way forward to an era where more ‘precise’ approaches – ‘precision’ nutrition – which leverage data on genetic variability alongside the traditional indices, have been put forth as the state-of-the-art solution to redress the effects of malnutrition across the life course. We purport that this inference is premature and that it is imperative to first review and critique the existing evidence from large-scale epidemiological findings. We set out to provide a critical evaluation of findings from genome-wide association studies (GWAS) in the roadmap to precision nutrition, focusing on GWAS of micronutrient disposition. We found that a large number of loci associated with biomarkers of micronutrient status have been identified. Mean estimates of heritability of micronutrient status ranged between 20 and 35 % for minerals, 56–59 % for water-soluble and 30–70 % for fat-soluble vitamins. With some exceptions, the majority of the identified genetic variants explained little of the overall variance in status for each micronutrient, ranging between 1·3 and 8 % (minerals), <0·1–12 % (water-soluble) and 1·7–2·3 % for (fat-soluble) vitamins. However, GWAS have provided some novel insight into mechanisms that underpin variability in micronutrient status. Our findings highlight obvious gaps that need to be addressed if the full scope of precision nutrition is ever to be realised, including research aimed at (i) dissecting the genetic basis of micronutrient deficiencies or ‘response’ to intake/supplementation (ii) identifying trans-ethnic and ethnic-specific effects (iii) identifying gene–nutrient interactions for the purpose of unravelling molecular ‘behaviour’ in a range of environmental contexts.
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12
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Nalado AM, Dickens C, Dix-Peek T, Mahlangu JN, Olorunfemi G, Paget G, Duarte R, Naicker S. TMPRSS6 rs855791 polymorphism and susceptibility to iron deficiency anaemia in non-dialysis chronic kidney disease patients in South Africa. INTERNATIONAL JOURNAL OF MOLECULAR EPIDEMIOLOGY AND GENETICS 2019; 10:1-9. [PMID: 30911357 PMCID: PMC6420716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 01/16/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND In genome-wide studies, there is a strong association between the TMPRSS6 allele A736V (rs855791) and significantly lower levels of serum iron, transferrin saturation, haemoglobin, and mean corpuscular volumes. The influence of this genetic variant on susceptibility to iron deficiency anaemia (IDA) in chronic kidney disease (CKD) patients is unknown. METHODS In this cross-sectional study, we measured the full blood count and TMPRSS6 T>C polymorphism in black adult participants (n=260) with CKD and healthy controls (n=146) at the Charlotte Maxeke Johannesburg Academic Hospital, South Africa. RESULTS The overall prevalence of anaemia in the CKD and control population was 46.9% and 19.6% respectively. Twenty-six per cent of CKD participants were iron deficient. The prevalence of rs855791 C homozygosity was similar among iron deficient and non-iron deficient anaemia groups (86.1% vs 84.2%, P=0.723). When the analysis was confined to subjects with or without functional iron deficiency anaemia, C homozygote (88.3% vs 84.4%, P=0.425) was similar for both groups. CONCLUSIONS Our study suggests that homozygosity for TMPRSS6 rs855791 C genotype does not influence IDA in non-dialysis CKD patients in our population.
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Affiliation(s)
- Aishatu Muhammad Nalado
- Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Science, University of The WitwatersrandJohannesburg, South Africa
- Department of Internal Medicine, College of Health Sciences, Bayero UniversityKano, Nigeria
| | - Caroline Dickens
- Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Science, University of The WitwatersrandJohannesburg, South Africa
| | - Therese Dix-Peek
- Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Science, University of The WitwatersrandJohannesburg, South Africa
| | - Johnny N Mahlangu
- School of Pathology, Faculty of Health Sciences, University of The WitwatersrandJohannesburg, South Africa
| | - Gbenga Olorunfemi
- Division of Epidemiology and Biostatistics, School of Public Health, University of The WitwatersrandJohannesburg, South Africa
| | - Graham Paget
- Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Science, University of The WitwatersrandJohannesburg, South Africa
| | - Raquel Duarte
- Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Science, University of The WitwatersrandJohannesburg, South Africa
| | - Saraladevi Naicker
- Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Science, University of The WitwatersrandJohannesburg, South Africa
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13
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Tao Y, Huang X, Xie Y, Zhou X, He X, Tang S, Liao M, Chen Y, Tan A, Chen Y, Wang Q, Mo Z. Genome-wide association and gene-environment interaction study identifies variants in ALDH2 associated with serum ferritin in a Chinese population. Gene 2019; 685:196-201. [DOI: 10.1016/j.gene.2018.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 08/28/2018] [Accepted: 11/01/2018] [Indexed: 10/27/2022]
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14
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Kallianpur AR, Gerschenson M, Hulgan T, Kaur H, Clifford DB, Haas DW, Murdock DG, McArthur JC, Samuels DC, Simpson DM. Hemochromatosis (HFE) Gene Variants Are Associated with Increased Mitochondrial DNA Levels During HIV-1 Infection and Antiretroviral Therapy. AIDS Res Hum Retroviruses 2018; 34:942-949. [PMID: 29968489 PMCID: PMC6421985 DOI: 10.1089/aid.2018.0025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Some HIV-associated complications involve mitochondrial dysfunction and may be less common in individuals with iron-loading HFE (hemochromatosis gene) variants. We evaluated HFE 845A and 187G alleles in relation to mitochondrial DNA (mtDNA) levels in peripheral blood mononuclear cells from 85 individuals with HIV infection on uninterrupted antiretroviral therapy (ART) for 15 or more consecutive weeks. Carriers of HFE gene variants (N = 24) had significantly higher mtDNA levels than noncarriers (N = 61), after adjusting for age, race, sex, and type of ART [adjusted β-coefficient 297, p-value < .001 for at least one HFE variant], but mtDNA declined among all individuals on study during 48 weeks on ART. Increased cellular mtDNA content may represent a compensatory response to mitochondrial stress that is influenced by iron-loading HFE variants.
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Affiliation(s)
- Asha R. Kallianpur
- Department of Genomic Medicine, Cleveland Clinic Foundation/Lerner Research Institute, Cleveland, Ohio
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio
| | - Mariana Gerschenson
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Todd Hulgan
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Harpreet Kaur
- Department of Genomic Medicine, Cleveland Clinic Foundation/Lerner Research Institute, Cleveland, Ohio
| | - David B. Clifford
- Department of Neurology, Washington University in Saint Louis, St. Louis, Missouri
| | - David W. Haas
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Deborah G. Murdock
- Children's Hospital of Philadelphia Research Institute & Center for Mitochondrial and Epigenomic Medicine, Philadelphia, Pennsylvania
| | - Justin C. McArthur
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - David C. Samuels
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
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15
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Wawer AA, Jennings A, Fairweather-Tait SJ. Iron status in the elderly: A review of recent evidence. Mech Ageing Dev 2018; 175:55-73. [PMID: 30040993 DOI: 10.1016/j.mad.2018.07.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 06/25/2018] [Accepted: 07/12/2018] [Indexed: 12/22/2022]
Abstract
A comprehensive literature review of iron status in the elderly was undertaken in order to update a previous review (Fairweather-Tait et al, 2014); 138 summarised papers describe research on the magnitude of the problem, aetiology and age-related physiological changes that may affect iron status, novel strategies for assessing iron status with concurrent health conditions, hepcidin, lifestyle factors, iron supplements, iron status and health outcomes (bone mineral density, frailty, inflammatory bowel disease, kidney failure, cancer, cardiovascular, and neurodegenerative diseases). Each section of this review concludes with key points from the relevant papers. The overall findings were that disturbed iron metabolism plays a major role in a large number of conditions associated with old age. Correction of iron deficiency/overload may improve disease prognosis, but diagnosis of iron deficiency requires appropriate cut-offs for biomarkers of iron status in elderly men and women to be agreed. Iron deficiency (with or without anemia), anemia of inflammation, and anemia of chronic disease are all widespread in the elderly and, once identified, should be investigated further as they are often indicative of underlying disease. Management options should be reviewed and updated, and novel therapies, which show potential for treating anemia of inflammation or chronic disease, should be considered.
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Affiliation(s)
- Anna A Wawer
- Discipline of Medicine, University of Adelaide, The Queen Elizabeth Hospital and the Basil Hetzel Institute for Translational Health Research, Woodville, 5011, South Australia, Australia
| | - Amy Jennings
- Norwich Medical School, University of East Anglia, Norwich, NR4 7TJ, UK
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16
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Mills NT, Maier R, Whitfield JB, Wright MJ, Colodro-Conde L, Byrne EM, Scott JG, Byrne GJ, Hansell NK, Vinkhuyzen AAE, CouvyDuchesne B, Montgomery GW, Henders AK, Martin NG, Wray NR, Benyamin B. Investigating the relationship between iron and depression. J Psychiatr Res 2017; 94:148-155. [PMID: 28715705 DOI: 10.1016/j.jpsychires.2017.07.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 06/03/2017] [Accepted: 07/07/2017] [Indexed: 12/22/2022]
Abstract
Lower levels of circulating iron have been associated with depression. Our objective was to investigate the phenotypic and genetic relationship between measures of circulating levels of iron (serum iron, transferrin, transferrin saturation, and ferritin) and depressive symptoms. Data were available from ongoing studies at QIMR Berghofer Medical Research Institute (QIMRB), including twin adolescents (mean age 15.1 years, standard deviation (SD) 3.2 years), and twin adults (mean age 23.2 years, SD 2.2 years). In the adolescent cohort, there were 3416 participants from 1688 families. In the adult cohort there were 9035 participants from 4533 families. We estimated heritabilities of, and phenotypic and genetic correlations between, traits. We conducted analyses that linked results from published large-scale genome-wide association studies (including iron and Major Depressive Disorder) with our study samples using single SNP and multi-SNP genetic risk score analyses, and LD score regression analyses. In both cohorts, measures of iron, transferrin, transferrin saturation, and log 10 of ferritin (L10Fer) were all highly heritable, while depressive measures were moderately heritable. In adolescents, depression measures were higher in those in the middle 10th versus top 10th percentile of transferrin saturation measures (p = 0.002). Genetic profile risk scores of the iron measures were not significantly associated with depression in study participants. LD score analyses showed no significant genetic relationship between iron and depression. Genetic factors strongly influence iron measures in adolescents and adults. Using several different strategies we find no evidence for a genetic contribution to the relationship between blood measures of iron and measures of depression.
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Affiliation(s)
- Natalie T Mills
- Genetic Epidemiology, QIMR Berghofer Medical Research Institute, Brisbane, 4006, Australia; Discipline of Psychiatry, School of Medicine, University of Adelaide, Adelaide, 5000, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, 4072, Australia.
| | - Robert Maier
- Queensland Brain Institute, The University of Queensland, Brisbane, 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072, Australia
| | - John B Whitfield
- Genetic Epidemiology, QIMR Berghofer Medical Research Institute, Brisbane, 4006, Australia
| | - Margaret J Wright
- Queensland Brain Institute, The University of Queensland, Brisbane, 4072, Australia
| | - Lucia Colodro-Conde
- Psychiatric Genetics, QIMR Berghofer Medical Research Institute, Brisbane, 4006, Australia
| | - Enda M Byrne
- Queensland Brain Institute, The University of Queensland, Brisbane, 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072, Australia
| | - James G Scott
- The University of Queensland, UQ Centre for Clinical Research, Herston, 4029, Australia; Metro North Mental Health, Royal Brisbane and Women's Hospital, Brisbane, 4006, Australia; Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Brisbane, 4076, Australia
| | - Gerard J Byrne
- Academic Discipline of Psychiatry, School of Medicine, The University of Queensland, Brisbane, Australia
| | - Narelle K Hansell
- Queensland Brain Institute, The University of Queensland, Brisbane, 4072, Australia
| | - Anna A E Vinkhuyzen
- Queensland Brain Institute, The University of Queensland, Brisbane, 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072, Australia
| | - Baptiste CouvyDuchesne
- Genetic Epidemiology, QIMR Berghofer Medical Research Institute, Brisbane, 4006, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072, Australia
| | - Grant W Montgomery
- Queensland Brain Institute, The University of Queensland, Brisbane, 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072, Australia
| | - Anjali K Henders
- Queensland Brain Institute, The University of Queensland, Brisbane, 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072, Australia
| | - Nicholas G Martin
- Genetic Epidemiology, QIMR Berghofer Medical Research Institute, Brisbane, 4006, Australia
| | - Naomi R Wray
- Queensland Brain Institute, The University of Queensland, Brisbane, 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072, Australia
| | - Beben Benyamin
- Queensland Brain Institute, The University of Queensland, Brisbane, 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072, Australia
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17
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Raffield LM, Louie T, Sofer T, Jain D, Ipp E, Taylor KD, Papanicolaou GJ, Avilés-Santa L, Lange LA, Laurie CC, Conomos MP, Thornton TA, Chen YDI, Qi Q, Cotler S, Thyagarajan B, Schneiderman N, Rotter JI, Reiner AP, Lin HJ. Genome-wide association study of iron traits and relation to diabetes in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL): potential genomic intersection of iron and glucose regulation? Hum Mol Genet 2017; 26:1966-1978. [PMID: 28334935 DOI: 10.1093/hmg/ddx082] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 03/01/2017] [Indexed: 12/14/2022] Open
Abstract
Genetic variants contribute to normal variation of iron-related traits and may also cause clinical syndromes of iron deficiency or excess. Iron overload and deficiency can adversely affect human health. For example, elevated iron storage is associated with increased diabetes risk, although mechanisms are still being investigated. We conducted the first genome-wide association study of serum iron, total iron binding capacity (TIBC), transferrin saturation, and ferritin in a Hispanic/Latino cohort, the Hispanic Community Health Study/Study of Latinos (>12 000 participants) and also assessed the generalization of previously known loci to this population. We then evaluated whether iron-associated variants were associated with diabetes and glycemic traits. We found evidence for a novel association between TIBC and a variant near the gene for protein phosphatase 1, regulatory subunit 3B (PPP1R3B; rs4841132, β = -0.116, P = 7.44 × 10-8). The effect strengthened when iron deficient individuals were excluded (β = -0.121, P = 4.78 × 10-9). Ten of sixteen variants previously associated with iron traits generalized to HCHS/SOL, including variants at the transferrin (TF), hemochromatosis (HFE), fatty acid desaturase 2 (FADS2)/myelin regulatory factor (MYRF), transmembrane protease, serine 6 (TMPRSS6), transferrin receptor (TFR2), N-acetyltransferase 2 (arylamine N-acetyltransferase) (NAT2), ABO blood group (ABO), and GRB2 associated binding protein 3 (GAB3) loci. In examining iron variant associations with glucose homeostasis, an iron-raising variant of TMPRSS6 was associated with lower HbA1c levels (P = 8.66 × 10-10). This association was attenuated upon adjustment for iron measures. In contrast, the iron-raising allele of PPP1R3B was associated with higher levels of fasting glucose (P = 7.70 × 10-7) and fasting insulin (P = 4.79 × 10-6), but these associations were not attenuated upon adjustment for TIBC-so iron is not likely a mediator. These results provide new genetic information on iron traits and their connection with glucose homeostasis.
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Affiliation(s)
- Laura M Raffield
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Tin Louie
- Department of Biostatistics, University of Washington, Seattle, WA 98195, USA
| | - Tamar Sofer
- Department of Biostatistics, University of Washington, Seattle, WA 98195, USA
| | - Deepti Jain
- Department of Biostatistics, University of Washington, Seattle, WA 98195, USA
| | - Eli Ipp
- Department of Medicine and Division of Endocrinology, Harbor-UCLA Medical Center, Torrance, CA 90502, USA and the David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Kent D Taylor
- Institute for Translational Genomics and Population Sciences, Los Angeles Biomedical Research Institute, and Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA 90502, and the David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | | | | | - Leslie A Lange
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Cathy C Laurie
- Department of Biostatistics, University of Washington, Seattle, WA 98195, USA
| | - Matthew P Conomos
- Department of Biostatistics, University of Washington, Seattle, WA 98195, USA
| | - Timothy A Thornton
- Department of Biostatistics, University of Washington, Seattle, WA 98195, USA
| | - Yii-Der Ida Chen
- Institute for Translational Genomics and Population Sciences, Los Angeles Biomedical Research Institute, and Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA 90502, and the David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA 90502, and the David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Qibin Qi
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Scott Cotler
- Department of Medicine, Division of Hepatology, Loyola University Medical Center, Maywood, IL 60153, USA
| | - Bharat Thyagarajan
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Neil Schneiderman
- Department of Psychology and Behavioral Medicine, University of Miami, FL 33124, USA
| | - Jerome I Rotter
- Institute for Translational Genomics and Population Sciences, Los Angeles Biomedical Research Institute, and Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA 90502, and the David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA 90502, and the David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Alex P Reiner
- Department of Epidemiology, University of Washington, Seattle, WA 98195, USA
| | - Henry J Lin
- Institute for Translational Genomics and Population Sciences, Los Angeles Biomedical Research Institute, and Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA 90502, and the David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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18
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Genome-Wide Association Shows that Pigmentation Genes Play a Role in Skin Aging. J Invest Dermatol 2017; 137:1887-1894. [DOI: 10.1016/j.jid.2017.04.026] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 04/05/2017] [Accepted: 04/24/2017] [Indexed: 01/27/2023]
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Gichohi-Wainaina WN, Tanaka T, Towers GW, Verhoef H, Veenemans J, Talsma EF, Harryvan J, Boekschoten MV, Feskens EJ, Melse-Boonstra A. Associations between Common Variants in Iron-Related Genes with Haematological Traits in Populations of African Ancestry. PLoS One 2016; 11:e0157996. [PMID: 27332551 PMCID: PMC4917107 DOI: 10.1371/journal.pone.0157996] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 06/08/2016] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Large genome-wide association (GWA) studies of European ancestry individuals have identified multiple genetic variants influencing iron status. Studies on the generalizability of these associations to African ancestry populations have been limited. These studies are important given interethnic differences in iron status and the disproportionate burden of iron deficiency among African ancestry populations. METHODS We tested the associations of 20 previously identified iron status-associated single nucleotide polymorphisms (SNPs) in 628 Kenyans, 609 Tanzanians, 608 South Africans and 228 African Americans. In each study, we examined the associations present between 20 SNPs with ferritin and haemoglobin, adjusting for age, sex and CRP levels. RESULTS In the meta analysis including all 4 African ancestry cohorts, we replicated previously reported associations with lowered haemoglobin concentrations for rs2413450 (β = -0.19, P = 0.02) and rs4820268 (β = -0.16, P = 0.04) in TMPRSS6. An association with increased ferritin concentrations was also confirmed for rs1867504 in TF (β = 1.04, P = <0.0001) in the meta analysis including the African cohorts only. CONCLUSIONS In all meta analyses, we only replicated 4 of the 20 single nucleotide polymorphisms reported to be associated with iron status in large GWA studies of European ancestry individuals. While there is now evidence for the associations of a number of genetic variants with iron status in both European and African ancestry populations, the considerable lack of concordance highlights the importance of continued ancestry-specific studies to elucidate the genetic underpinnings of iron status in ethnically diverse populations.
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Affiliation(s)
- Wanjiku N. Gichohi-Wainaina
- Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands
- International institute of Tropical Agriculture (IITA), Dar es Salaam, Tanzania
| | - Toshiko Tanaka
- Translational Gerontology Branch, National Institute on Aging, Baltimore, MD, United States of America
| | - G. Wayne Towers
- Centre of Excellence for Nutrition, North-West University (Potchefstroom campus), Potchefstroom, South Africa
| | - Hans Verhoef
- Cell Biology and Immunology Group, Wageningen University, Wageningen, The Netherlands
- Medical Research Council (MRC) International Nutrition Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Medical Research Council Banjul, The Gambia
| | - Jacobien Veenemans
- Laboratory for Microbiology and Infection Control, Amphia Hospital, Breda, The Netherlands
- Department of Medical Microbiology and Immunology, Admiraal De Ruyter Hospital, Goes The Netherlands
| | - Elise F. Talsma
- Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands
- HarvestPlus, International Center for Tropical Agriculture (CIAT), Cali, Colombia
| | - Jan Harryvan
- Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands
| | - Mark V. Boekschoten
- Nutrition, Metabolism and Genomics group, Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands
| | - Edith J. Feskens
- Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands
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Lucijanić M, Pejša V, Mitrović Z, Štoos-Veić T, Livun A, Jakšić O, Vasilj T, Piršić M, Hariš V, Prka Ž, Kušec R. Hemochromatosis gene mutations may affect the survival of patients with myelodysplastic syndrome. Hematology 2016; 21:170-4. [PMID: 27077775 DOI: 10.1080/10245332.2015.1101964] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
OBJECTIVES The recent availability of potent oral iron chelators is renewing an interest in the assessment of the possible impact of HFE genetics in MDS. METHODS Thirty six newly diagnosed patients with MDS were studied for parameters of iron metabolism in addition to C282Y and H63D mutations of the HFE gene. RESULTS Mutations were present in 11 out of 36 patients (31%), which were not different from our general population and were equally distributed among MDS subtypes. Mutated patients had higher ferritin levels (P = 0.039) and lower TIBC (P = 0.018). Ferritin was found to be higher for the untransfused mutated patients (P = 0.017), but not for transfusion-dependent patients in whom ferritin levels correlated significantly with the number of blood units received (P = 0.04). There was no difference in the number of blood units received between the mutated and wild type patients. A new observation made was that the mutated patients had a lower overall survival in addition to a poorer leukemia free survival (LFS) (P = 0.004 and P = 0.003, respectively). DISCUSSION The HFE gene mutations are not more frequent in MDS patients. Iron overload in mutated patients was higher but there was no correlation found using supportive therapy for anemia. The effect of mutations on survival could be mediated by changes in iron metabolism. CONCLUSION The HFE genotype may predict MDS prognosis and there is a need for further studies. It remains a challenging question if HFE mutated MDS patients should be considered for potent iron chelation therapy.
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Affiliation(s)
- Marko Lucijanić
- a Department of Hematology , University Hospital Dubrava , Zagreb , Croatia
| | - Vlatko Pejša
- a Department of Hematology , University Hospital Dubrava , Zagreb , Croatia.,b University of Zagreb, School of Medicine , Zagreb , Croatia
| | - Zdravko Mitrović
- a Department of Hematology , University Hospital Dubrava , Zagreb , Croatia
| | - Tajana Štoos-Veić
- c Department of Clinical Cytology and Cytometry , University Hospital Dubrava , Zagreb , Croatia.,d University of Osijek, School of Medicine , Croatia
| | - Ana Livun
- e Clinical Institute of Laboratory Diagnosis, Division of Molecular Diagnosis and Genetics , University Hospital Dubrava , Zagreb , Croatia
| | - Ozren Jakšić
- a Department of Hematology , University Hospital Dubrava , Zagreb , Croatia.,b University of Zagreb, School of Medicine , Zagreb , Croatia
| | - Tamara Vasilj
- a Department of Hematology , University Hospital Dubrava , Zagreb , Croatia
| | - Mario Piršić
- a Department of Hematology , University Hospital Dubrava , Zagreb , Croatia
| | - Višnja Hariš
- a Department of Hematology , University Hospital Dubrava , Zagreb , Croatia
| | - Željko Prka
- a Department of Hematology , University Hospital Dubrava , Zagreb , Croatia
| | - Rajko Kušec
- a Department of Hematology , University Hospital Dubrava , Zagreb , Croatia.,b University of Zagreb, School of Medicine , Zagreb , Croatia.,d University of Osijek, School of Medicine , Croatia
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Association Studies of HFE C282Y and H63D Variants with Oral Cancer Risk and Iron Homeostasis Among Whites and Blacks. Cancers (Basel) 2015; 7:2386-96. [PMID: 26690219 PMCID: PMC4695898 DOI: 10.3390/cancers7040898] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/25/2015] [Accepted: 12/02/2015] [Indexed: 01/29/2023] Open
Abstract
Background: Polymorphisms in the hemochromatosis (HFE) gene are associated with excessive iron absorption from the diet, and pro-oxidant effects of iron accumulation are thought to be a risk factor for several types of cancer. Methods: The C282Y (rs1800562) and H63D (rs1799945) polymorphisms were genotyped in 301 oral cancer cases and 437 controls and analyzed in relation to oral cancer risk, and serum iron biomarker levels from a subset of 130 subjects. Results: Individuals with the C282Y allele had lower total iron binding capacity (TIBC) (321.2 ± 37.2 µg/dL vs. 397.7 ± 89.0 µg/dL, p = 0.007) and higher percent transferrin saturation (22.0 ± 8.7 vs. 35.6 ± 22.9, p = 0.023) than wild type individuals. Iron and ferritin levels approached significantly higher levels for the C282Y allele (p = 0.0632 and p = 0.0588, respectively). Conclusions: Iron biomarker levels were elevated by the C282Y allele, but neither (rs1800562) nor (rs1799945) was associated with oral cancer risk in blacks and whites.
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Gichohi-Wainaina WN, Melse-Boonstra A, Swinkels DW, Zimmermann MB, Feskens EJ, Towers GW. Common Variants and Haplotypes in the TF, TNF-α, and TMPRSS6 Genes Are Associated with Iron Status in a Female Black South African Population. J Nutr 2015; 145:945-53. [PMID: 25809685 DOI: 10.3945/jn.114.209148] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 03/10/2015] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND It is unknown whether single nucleotide polymorphisms (SNPs), associated with iron status in European and Asian populations, have the same relation within the African population. OBJECTIVES We investigated associations of reported SNPs with iron markers in a South African cohort. METHODS Hemoglobin concentration, serum ferritin (SF) and soluble transferrin receptor (sTfR) concentrations, and body iron (BI) stores were measured in women (n = 686; range, 32-86 y) who were part of the Prospective Urban and Rural Epidemiology study. Thirty-two SNPs in 12 genes were selected based on existing genome-wide association study data. RESULTS In the transferrin (TF) gene, SF and BI were significantly lower in the heterozygote genotype (AG) of reference SNP (rs) 1799852 (P = 0.01 and 0.03, respectively) and sTfR concentrations were significantly higher (P = 0.004) than the homozygote minor allele genotype (AA), whereas transferrin receptor and BI concentrations were significantly lower in the heterozygote genotype (AG) of rs3811647 (both P = 0.03) than the homozygote wild-type (AA) and minor allele groups (GG). The chromosome 6 allele combination (AAA) consisting of rs1799964 and rs1800629 both in tumor necrosis factor-α (TNF-α) and rs2071592 in nuclear factor κB inhibitor-like protein 1 (NFKBIL1) was associated with higher odds for low SF concentrations (SF < 15 μg/L; OR: 1.86; 95% CI: 1.23, 2.79) than the allele combinations AGA, GGT, and AGT. The chromosome 22 allele combination (GG) consisting of rs228918 and rs228921 in the transmembrane protease serine 6 (TMPRSS6) gene was associated with lower odds for increased sTfR concentrations (sTfR > 8.3mg/L; OR: 0.79; 95% CI: 0.63, 0.98) than the allele combination AA. CONCLUSIONS Various SNPs and allele combinations in the TF, TNF-α, and TMPRSS6 genes are associated with iron status in black South African women; however, these association patterns are different compared with European ancestry populations. This stresses the need for population-specific genomic data.
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Affiliation(s)
| | - Alida Melse-Boonstra
- Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands;
| | - Dorine W Swinkels
- The Laboratory of Genetic, Endocrine, and Metabolic Diseases, Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Michael B Zimmermann
- Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands; Laboratory of Human Nutrition, Institute of Food Nutrition and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology, Zurich, Switzerland; and
| | - Edith J Feskens
- Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands
| | - G Wayne Towers
- Center of Excellence for Nutrition, North-West University, Potchefstroom, South Africa
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Lee SM, Loguinov A, Fleming RE, Vulpe CD. Effects of strain and age on hepatic gene expression profiles in murine models of HFE-associated hereditary hemochromatosis. GENES AND NUTRITION 2014; 10:443. [PMID: 25427953 DOI: 10.1007/s12263-014-0443-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 11/15/2014] [Indexed: 12/20/2022]
Abstract
Hereditary hemochromatosis is an iron overload disorder most commonly caused by a defect in the HFE gene. While the genetic defect is highly prevalent, the majority of individuals do not develop clinically significant iron overload, suggesting the importance of genetic modifiers. Murine hfe knockout models have demonstrated that strain background has a strong effect on the severity of iron loading. We noted that hepatic iron loading in hfe-/- mice occurs primarily over the first postnatal weeks (loading phase) followed by a timeframe of relatively static iron concentrations (plateau phase). We thus evaluated the effects of background strain and of age on hepatic gene expression in Hfe knockout mice (hfe-/-). Hepatic gene expression profiles were examined using cDNA microarrays in 4- and 8-week-old hfe-/- and wild-type mice on two different genetic backgrounds, C57BL/6J (C57) and AKR/J (AKR). Genes differentially regulated in all hfe-/- mice groups, compared with wild-type mice, including those involved in cell survival, stress and damage responses and lipid metabolism. AKR strain-specific changes in lipid metabolism genes and C57 strain-specific changes in cell adhesion and extracellular matrix protein genes were detected in hfe-/- mice. Mouse strain and age are each significantly associated with hepatic gene expression profiles in hfe-/- mice. These affects may underlie or reflect differences in iron loading in these mice.
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Affiliation(s)
- Seung-Min Lee
- Department of Food and Nutrition, College of Human Ecology, Yonsei University, Seoul, South Korea,
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25
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Novel loci affecting iron homeostasis and their effects in individuals at risk for hemochromatosis. Nat Commun 2014; 5:4926. [PMID: 25352340 PMCID: PMC4215164 DOI: 10.1038/ncomms5926] [Citation(s) in RCA: 192] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 08/06/2014] [Indexed: 12/13/2022] Open
Abstract
Variation in body iron is associated with or causes diseases, including anaemia and iron overload. Here, we analyse genetic association data on biochemical markers of iron status from 11 European-population studies, with replication in eight additional cohorts (total up to 48,972 subjects). We find 11 genome-wide-significant (P<5 × 10(-8)) loci, some including known iron-related genes (HFE, SLC40A1, TF, TFR2, TFRC, TMPRSS6) and others novel (ABO, ARNTL, FADS2, NAT2, TEX14). SNPs at ARNTL, TF, and TFR2 affect iron markers in HFE C282Y homozygotes at risk for hemochromatosis. There is substantial overlap between our iron loci and loci affecting erythrocyte and lipid phenotypes. These results will facilitate investigation of the roles of iron in disease.
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Liao M, Shi J, Huang L, Gao Y, Tan A, Wu C, Lu Z, Yang X, Zhang S, Hu Y, Qin X, Li J, Chen G, Xu J, Mo Z, Zhang H. Genome-wide association study identifies variants in PMS1 associated with serum ferritin in a Chinese population. PLoS One 2014; 9:e105844. [PMID: 25162662 PMCID: PMC4146590 DOI: 10.1371/journal.pone.0105844] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 07/24/2014] [Indexed: 01/11/2023] Open
Abstract
Only a small proportion of genetic variation in serum ferritin has been explained by variant genetic studies, and genome-wide association study (GWAS) for serum ferritin has not been investigated widely in Chinese population. We aimed at exploring the novel genetic susceptibility to serum ferritin, and performed this two stage GWAS in a healthy Chinese population of 3,495 men aged 20–69 y, including 1,999 unrelated subjects in the first stage and 1,496 independent individuals in the second stage. Serum ferritin was measured with electrochemiluminescence immunoassay, and DNA samples were collected for genotyping. A total of 1,940,243 SNPs were tested by using multivariate linear regression analysis. After adjusting for population stratification, age and BMI, the rs5742933 located in the 5′UTR region of PMS1 gene on chromosome 2 was the most significantly associated with ferritin concentrations (P-combined = 2.329×10−10) (β = −0.11, 95% CI: −0.14, −0.07). Moreover, this marker was about 200kb away from the candidate gene SLC40A1 which is responsible for iron export. PMS1 gene was the novel genetic susceptibility to serum ferritin in Chinese males and its relation to SLC40A1 needs further study.
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Affiliation(s)
- Ming Liao
- Institute of Urology and Nephrology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, PR China
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, PR China
| | - Jianying Shi
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, PR China
| | - Lirong Huang
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, PR China
| | - Yong Gao
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, PR China
| | - Aihua Tan
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, PR China
| | - Chunlei Wu
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, PR China
- Urology Department, First Affiliated Hospital of Xinxiang Medical College, Xinxiang, Henan Province, China
| | - Zheng Lu
- Institute of Urology and Nephrology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, PR China
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, PR China
| | - Xiaobo Yang
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, PR China
- School of Public Health, Guangxi Medical University, Nanning, Guangxi, PR China
| | - Shijun Zhang
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, PR China
- Department of Pharmacology, Guangxi Medical University, Nanning, Guangxi, PR China
| | - Yanlin Hu
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, PR China
- Medical Scientific Research Center, Guangxi Medical University, Nanning, Guangxi, PR China
| | - Xue Qin
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, PR China
- Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, PR China
| | - Jianling Li
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, PR China
- Institute of Cardiovascular Disease, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, PR China
| | - Gang Chen
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, PR China
- Pathology Department, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, PR China
| | - Jianfeng Xu
- Center for Cancer Genomics, Wake Forest University, School of Medicine, Winston-Salem, North Carolina, United States of America
- Center for Genetic Epidemiology, Van Andel Research Institute, Grand Rapids, Michigan, United States of America
| | - Zengnan Mo
- Institute of Urology and Nephrology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, PR China
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, PR China
| | - Haiying Zhang
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, PR China
- School of Public Health, Guangxi Medical University, Nanning, Guangxi, PR China
- General Practice School, Guangxi Medical University, Nanning, Guangxi, China
- * E-mail:
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Rossi E, Olynyk JK, Jeffrey GP. Clinical penetrance of C282Y homozygousHFEhemochromatosis. Expert Rev Hematol 2014; 1:205-16. [DOI: 10.1586/17474086.1.2.205] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Fairweather-Tait SJ, Guile GR, Valdes AM, Wawer AA, Hurst R, Skinner J, Macgregor AJ. The contribution of diet and genotype to iron status in women: a classical twin study. PLoS One 2013; 8:e83047. [PMID: 24391736 PMCID: PMC3876997 DOI: 10.1371/journal.pone.0083047] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 11/08/2013] [Indexed: 11/19/2022] Open
Abstract
This is the first published report examining the combined effect of diet and genotype on body iron content using a classical twin study design. The aim of this study was to determine the relative contribution of genetic and environmental factors in determining iron status. The population was comprised of 200 BMI- and age-matched pairs of MZ and DZ healthy twins, characterised for habitual diet and 15 iron-related candidate genetic markers. Variance components analysis demonstrated that the heritability of serum ferritin (SF) and soluble transferrin receptor was 44% and 54% respectively. Measured single nucleotide polymorphisms explained 5% and selected dietary factors 6% of the variance in iron status; there was a negative association between calcium intake and body iron (p = 0.02) and SF (p = 0.04).
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Affiliation(s)
| | - Geoffrey R. Guile
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Ana M. Valdes
- Department of Twin Research & Genetic Epidemiology, King's College, London, United Kingdom
| | - Anna A. Wawer
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Rachel Hurst
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Jane Skinner
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
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Jahanshad N, Rajagopalan P, Thompson PM. Neuroimaging, nutrition, and iron-related genes. Cell Mol Life Sci 2013; 70:4449-61. [PMID: 23817740 PMCID: PMC3827893 DOI: 10.1007/s00018-013-1369-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 04/23/2013] [Accepted: 05/13/2013] [Indexed: 02/08/2023]
Abstract
Several dietary factors and their genetic modifiers play a role in neurological disease and affect the human brain. The structural and functional integrity of the living brain can be assessed using neuroimaging, enabling large-scale epidemiological studies to identify factors that help or harm the brain. Iron is one nutritional factor that comes entirely from our diet, and its storage and transport in the body are under strong genetic control. In this review, we discuss how neuroimaging can help to identify associations between brain integrity, genetic variations, and dietary factors such as iron. We also review iron's essential role in cognition, and we note some challenges and confounds involved in interpreting links between diet and brain health. Finally, we outline some recent discoveries regarding the genetics of iron and its effects on the brain, suggesting the promise of neuroimaging in revealing how dietary factors affect the brain.
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Affiliation(s)
- Neda Jahanshad
- Imaging Genetics Center, Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Neuroscience Research Building 225E, 635 Charles Young Drive, Los Angeles, CA 90095-1769 USA
| | - Priya Rajagopalan
- Imaging Genetics Center, Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Neuroscience Research Building 225E, 635 Charles Young Drive, Los Angeles, CA 90095-1769 USA
| | - Paul M. Thompson
- Imaging Genetics Center, Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Neuroscience Research Building 225E, 635 Charles Young Drive, Los Angeles, CA 90095-1769 USA
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30
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Rhodes SL, Buchanan DD, Ahmed I, Taylor KD, Loriot MA, Sinsheimer JS, Bronstein JM, Elbaz A, Mellick GD, Rotter JI, Ritz B. Pooled analysis of iron-related genes in Parkinson's disease: association with transferrin. Neurobiol Dis 2013; 62:172-8. [PMID: 24121126 DOI: 10.1016/j.nbd.2013.09.019] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 08/31/2013] [Accepted: 09/27/2013] [Indexed: 01/04/2023] Open
Abstract
Pathologic features of Parkinson's disease (PD) include death of dopaminergic neurons in the substantia nigra, presence of α-synuclein containing Lewy bodies, and iron accumulation in PD-related brain regions. The observed iron accumulation may be contributing to PD etiology but it also may be a byproduct of cell death or cellular dysfunction. To elucidate the possible role of iron accumulation in PD, we investigated genetic variation in 16 genes related to iron homeostasis in three case-control studies from the United States, Australia, and France. After screening 90 haplotype tagging single nucleotide polymorphisms (SNPs) within the genes of interest in the US study population, we investigated the five most promising gene regions in two additional independent case-control studies. For the pooled data set (1289 cases, 1391 controls) we observed a protective association (OR=0.83, 95% CI: 0.71-0.96) between PD and a haplotype composed of the A allele at rs1880669 and the T allele at rs1049296 in transferrin (TF; GeneID: 7018). Additionally, we observed a suggestive protective association (OR=0.87, 95% CI: 0.74-1.02) between PD and a haplotype composed of the G allele at rs10247962 and the A allele at rs4434553 in transferrin receptor 2 (TFR2; GeneID: 7036). We observed no associations in our pooled sample for haplotypes in SLC40A1, CYB561, or HFE. Taken together with previous findings in model systems, our results suggest that TF or a TF-TFR2 complex may have a role in the etiology of PD, possibly through iron misregulation or mitochondrial dysfunction within dopaminergic neurons.
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Affiliation(s)
- Shannon L Rhodes
- Department of Epidemiology, UCLA Fielding School of Public Health, 650 Charles E. Young Drive S, Los Angeles, CA 90095-1772, USA.
| | - Daniel D Buchanan
- Cancer and Population Studies Group, Queensland Institute of Medical Research, 300 Herston Rd, Brisbane, QLD 4006, Australia; University of Queensland, School of Medicine, Brisbane, Australia; Princess Alexandra Hospital, Australia
| | - Ismaïl Ahmed
- Centre for Research in Epidemiology and Population Health, Biostatistics team, INSERM U1018, F-94276 le Kremlin Bicêtre, France; Univ Paris-Sud, UMRS 1018, F-94276 le Kremlin Bicêtre, France
| | - Kent D Taylor
- Institute for Translational Genomics and Population Sciences, Los Angeles Biomedical Research Institute, Harbor-UCLA Medical Center, 1124 West Carson, Bldg E5, Torrance, CA 90502, USA
| | - Marie-Anne Loriot
- Sorbonne Paris Cité, Université Paris Descartes, INSERM UMR-S 775, France; Assistance Publique Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Service de Biochimie, Unité Fonctionnelle de Pharmacogénétique et Oncologie Moléculaire, France
| | - Janet S Sinsheimer
- Department of Human Genetics, David Geffen School of Medicine at UCLA, 695 Charles E. Young Drive South, Box 708822, Los Angeles, CA 90095-7088, USA; Department of Biomathematics, David Geffen School of Medicine at UCLA, Box 951766, Room 5303 Life Sciences, Los Angeles, CA 90095-1766, USA; Department of Biostatistics, UCLA Fielding School of Public Health, 650 Charles E. Young Drive S, Los Angeles, CA 90095-1772, USA
| | - Jeff M Bronstein
- Department of Neurology, David Geffen School of Medicine at UCLA, 710 Westwood Plaza, Los Angeles, CA 90095-1769, USA
| | - Alexis Elbaz
- Centre for Research in Epidemiology and Population Health, Social and Occupational Determinants of Health, INSERM U1018, F-94807 Villejuif, France; Univ Versailles St-Quentin, UMRS 1018, F-94807, Villejuif France
| | - George D Mellick
- Eskitis Institute for Drug Discovery, Griffith University, Nathan 4111, Brisbane, Australia; Department of Neurology, Princess Alexandra Hospital, Brisbane, Australia
| | - Jerome I Rotter
- Institute for Translational Genomics and Population Sciences, Los Angeles Biomedical Research Institute, Harbor-UCLA Medical Center, 1124 West Carson, Bldg E5, Torrance, CA 90502, USA
| | - Beate Ritz
- Department of Epidemiology, UCLA Fielding School of Public Health, 650 Charles E. Young Drive S, Los Angeles, CA 90095-1772, USA; Department of Neurology, David Geffen School of Medicine at UCLA, 710 Westwood Plaza, Los Angeles, CA 90095-1769, USA; Department of Environmental Health Sciences, UCLA Fielding School of Public Health, 650 Charles E. Young Drive S, Los Angeles, CA 90095-1772, USA
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Alkhateeb A, Al-khatib S, Elbetieha A, Al-Rashaideh T. Clinical characteristics and analysis of HFE gene variants (C282Y and H63D) in Jordanian Arab patients with age-related macular degeneration. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2013. [DOI: 10.1016/j.ejmhg.2012.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Oexle K, Schormair B, Ried JS, Czamara D, Heim K, Frauscher B, Högl B, Trenkwalder C, Martin Fiedler G, Thiery J, Lichtner P, Prokisch H, Specht M, Müller-Myhsok B, Döring A, Gieger C, Peters A, Wichmann HE, Meitinger T, Winkelmann J. Dilution of candidates: the case of iron-related genes in restless legs syndrome. Eur J Hum Genet 2013; 21:410-4. [PMID: 22929029 PMCID: PMC3598324 DOI: 10.1038/ejhg.2012.193] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 07/09/2012] [Accepted: 07/19/2012] [Indexed: 11/08/2022] Open
Abstract
Restless legs syndrome (RLS) is a common multifactorial disease. Some genetic risk factors have been identified. RLS susceptibility also has been related to iron. We therefore asked whether known iron-related genes are candidates for association with RLS and, vice versa, whether known RLS-associated loci influence iron parameters in serum. RLS/control samples (n = 954/1814 in the discovery step, 735/736 in replication 1, and 736/735 in replication 2) were tested for association with SNPs located within 4 Mb intervals surrounding each gene from a list of 111 iron-related genes using a discovery threshold of P = 5 × 10(-4). Two population cohorts (KORA F3 and F4 with together n = 3447) were tested for association of six known RLS loci with iron, ferritin, transferrin, transferrin-saturation, and soluble transferrin receptor. Results were negative. None of the candidate SNPs at the iron-related gene loci was confirmed significantly. An intronic SNP, rs2576036, of KATNAL2 at 18q21.1 was significant in the first (P = 0.00085) but not in the second replication step (joint nominal P-value = 0.044). Especially, rs1800652 (C282Y) in the HFE gene did not associate with RLS. Moreover, SNPs at the known RLS loci did not significantly affect serum iron parameters in the KORA cohorts. In conclusion, the correlation between RLS and iron parameters in serum may be weaker than assumed. Moreover, in a general power analysis, we show that genetic effects are diluted if they are transmitted via an intermediate trait to an end-phenotype. Sample size formulas are provided for small effect sizes.
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Affiliation(s)
- Konrad Oexle
- Institute of Human Genetics, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany.
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Gurrin LC, Turkovic L. COMBINING INDIVIDUAL PARTICIPANT DATA AND SUMMARY STATISTICS FROM BOTH CONTINUOUSLY VALUED AND BINARY VARIABLES TO ESTIMATE REGRESSION PARAMETERS. AUST NZ J STAT 2012. [DOI: 10.1111/j.1467-842x.2012.00647.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Gan W, Guan Y, Wu Q, An P, Zhu J, Lu L, Jing L, Yu Y, Ruan S, Xie D, Makrides M, Gibson RA, Anderson GJ, Li H, Lin X, Wang F. Association of TMPRSS6 polymorphisms with ferritin, hemoglobin, and type 2 diabetes risk in a Chinese Han population. Am J Clin Nutr 2012; 95:626-32. [PMID: 22301935 DOI: 10.3945/ajcn.111.025684] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Transmembrane protease serine 6 (TMPRSS6) regulates iron homeostasis by inhibiting the expression of hepcidin. Multiple common variants in TMPRSS6 were significantly associated with serum iron in recent genome-wide association studies, but their effects in the Chinese remain to be elucidated. OBJECTIVE The objective was to determine whether the TMPRSS6 single nucleotide polymorphisms (SNPs) rs855791(V736A) and rs4820268(D521D) were associated with blood hemoglobin and plasma ferritin concentrations and risk of type 2 diabetes in Chinese individuals. DESIGN The SNPs rs855791(V736A) and rs4820268(D521D) in the TMPRSS6 gene were genotyped and tested for their associations with plasma iron and type 2 diabetes risk in 1574 unrelated Chinese Hans from Beijing. RESULTS The 2 TMPRSS6 SNPs rs855791(V736A) and rs4820268(D521D) were both significantly associated with plasma ferritin (P ≤ 0.0058), hemoglobin (P ≤ 0.0013), iron overload risk (P ≤ 0.0068), and type 2 diabetes risk (P ≤ 0.0314). None of the associations with hemoglobin or plasma ferritin remained significant (P ≥ 0.1229) when the 2 variants were both included in one linear regression model. A haplotype carrying both iron-lowering alleles from the 2 TMPRSS SNPs showed significant associations with lower hemoglobin (P = 0.0014), lower plasma ferritin (P = 0.0027), and a reduced risk of iron overload (P = 0.0017) and of type 2 diabetes (P = 0.0277). CONCLUSIONS These findings suggest that TMPRSS6 variants were significantly associated with plasma ferritin, hemoglobin, risk of iron overload, and type 2 diabetes in Chinese Hans. The type 2 diabetes risk conferred by the TMPRSS6 SNPs is possibly mediated by plasma ferritin.
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Affiliation(s)
- Wei Gan
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, China
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Wiart A, Jepson A, Banya W, Bennett S, Whittle H, Martin NG, Hill AVS. Quantitative Association Tests of Immune Responses to Antigens ofMycobacterium Tuberculosis: A Study of Twins in West Africa. ACTA ACUST UNITED AC 2012. [DOI: 10.1375/twin.7.6.578] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
AbstractThere is now considerable evidence that host genetic factors are important in determining the outcome of infection withMycobacterium tuberculosis(MTB). The aim of this study was to assess the role of several candidate genes in the variation observed in the immune responses to MTB antigens. In-vitro assays of T-cell proliferation, an in-vivo intradermal delayed hypersensitivity response; cytokine and antibody secretions to several mycobacterial peptide antigens were assessed in healthy, but exposed, West African twins. Candidate gene polymorphisms were typed in theNRAMP1,Vitamin D receptor,IL10,IL4,IL4 receptorandCTLA-4genes. Variants of the lociIL10(−1082 G/A),CTLA-4(49 A/G) and theIL4 receptor(128 A/G) showed significant associations with immune responses to several antigens. T-cell proliferative responses and antibody responses were reduced, TNF-α responses were increased for subjects with theCTLA-4G allele. The T-cell proliferative responses of subjects withIL10GA and GG genotypes differed significantly.IL4 receptorAG and GG genotypes also showed significant differences in their T-cell proliferative responses to MTB antigens. These results yield a greater understanding of the genetic mechanisms that underlie the immune responses in tuberculosis and have implications for the design of therapeutic interventions.
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An P, Wu Q, Wang H, Guan Y, Mu M, Liao Y, Zhou D, Song P, Wang C, Meng L, Man Q, Li L, Zhang J, Wang F. TMPRSS6, but not TF, TFR2 or BMP2 variants are associated with increased risk of iron-deficiency anemia. Hum Mol Genet 2012; 21:2124-31. [DOI: 10.1093/hmg/dds028] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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Brain structure in healthy adults is related to serum transferrin and the H63D polymorphism in the HFE gene. Proc Natl Acad Sci U S A 2012; 109:E851-9. [PMID: 22232660 DOI: 10.1073/pnas.1105543109] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Control of iron homeostasis is essential for healthy central nervous system function: iron deficiency is associated with cognitive impairment, yet iron overload is thought to promote neurodegenerative diseases. Specific genetic markers have been previously identified that influence levels of transferrin, the protein that transports iron throughout the body, in the blood and brain. Here, we discovered that transferrin levels are related to detectable differences in the macro- and microstructure of the living brain. We collected brain MRI scans from 615 healthy young adult twins and siblings, of whom 574 were also scanned with diffusion tensor imaging at 4 Tesla. Fiber integrity was assessed by using the diffusion tensor imaging-based measure of fractional anisotropy. In bivariate genetic models based on monozygotic and dizygotic twins, we discovered that partially overlapping additive genetic factors influenced transferrin levels and brain microstructure. We also examined common variants in genes associated with transferrin levels, TF and HFE, and found that a commonly carried polymorphism (H63D at rs1799945) in the hemochromatotic HFE gene was associated with white matter fiber integrity. This gene has a well documented association with iron overload. Our statistical maps reveal previously unknown influences of the same gene on brain microstructure and transferrin levels. This discovery may shed light on the neural mechanisms by which iron affects cognition, neurodevelopment, and neurodegeneration.
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Blanco-Rojo R, Baeza-Richer C, López-Parra AM, Pérez-Granados AM, Brichs A, Bertoncini S, Buil A, Arroyo-Pardo E, Soria JM, Vaquero MP. Four variants in transferrin and HFE genes as potential markers of iron deficiency anaemia risk: an association study in menstruating women. Nutr Metab (Lond) 2011; 8:69. [PMID: 21978626 PMCID: PMC3195693 DOI: 10.1186/1743-7075-8-69] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 10/06/2011] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Iron deficiency anaemia is a worldwide health problem in which environmental, physiologic and genetic factors play important roles. The associations between iron status biomarkers and single nucleotide polymorphisms (SNPs) known to be related to iron metabolism were studied in menstruating women. METHODS A group of 270 Caucasian menstruating women, a population group at risk of iron deficiency anaemia, participated in the study. Haematological and biochemical parameters were analysed and 10 selected SNPs were genotyped by minisequencing assay. The associations between genetic and biochemical data were analysed by Bayesian Model Averaging (BMA) test and decision trees. Dietary intake of a representative subgroup of these volunteers (n = 141) was assessed, and the relationship between nutrients and iron biomarkers was also determined by linear regression. RESULTS Four variants, two in the transferrin gene (rs3811647, rs1799852) and two in the HFE gene (C282Y, H63D), explain 35% of the genetic variation or heritability of serum transferrin in menstruating women. The minor allele of rs3811647 was associated with higher serum transferrin levels and lower transferrin saturation, while the minor alleles of rs1799852 and the C282Y and H63D mutations of HFE were associated with lower serum transferrin levels. No association between nutrient intake and iron biomarkers was found. CONCLUSIONS In contrast to dietary intake, these four SNPs are strongly associated with serum transferrin. Carriers of the minor allele of rs3811647 present a reduction in iron transport to tissues, which might indicate higher iron deficiency anaemia risk, although the simultaneous presence of the minor allele of rs1799852 and HFE mutations appear to have compensatory effects. Therefore, it is suggested that these genetic variants might potentially be used as markers of iron deficiency anaemia risk.
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Affiliation(s)
- Ruth Blanco-Rojo
- Department of Metabolism and Nutrition, Institute of Food Science and Technology and Nutrition (ICTAN), Spanish National Research Council (CSIC), Madrid, Spain
| | - Carlos Baeza-Richer
- Department of Toxicology and Health Legislation, Faculty of Medicine, Complutense University of Madrid, Spain
| | - Ana M López-Parra
- Department of Toxicology and Health Legislation, Faculty of Medicine, Complutense University of Madrid, Spain
| | - Ana M Pérez-Granados
- Department of Metabolism and Nutrition, Institute of Food Science and Technology and Nutrition (ICTAN), Spanish National Research Council (CSIC), Madrid, Spain
| | - Anna Brichs
- Unit of Genomic of Complex Diseases, Institute of Biomedical Research (II-B Sant Pau), Barcelona, Spain
| | - Stefania Bertoncini
- Department of Toxicology and Health Legislation, Faculty of Medicine, Complutense University of Madrid, Spain
- Department of Biology, University of Pisa, Pisa, Italy
| | - Alfonso Buil
- Unit of Genomic of Complex Diseases, Institute of Biomedical Research (II-B Sant Pau), Barcelona, Spain
| | - Eduardo Arroyo-Pardo
- Department of Toxicology and Health Legislation, Faculty of Medicine, Complutense University of Madrid, Spain
| | - Jose M Soria
- Unit of Genomic of Complex Diseases, Institute of Biomedical Research (II-B Sant Pau), Barcelona, Spain
| | - M Pilar Vaquero
- Department of Metabolism and Nutrition, Institute of Food Science and Technology and Nutrition (ICTAN), Spanish National Research Council (CSIC), Madrid, Spain
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Gibson JN, Jellen LC, Unger EL, Morahan G, Mehta M, Earley CJ, Allen RP, Lu L, Jones BC. Genetic analysis of iron-deficiency effects on the mouse spleen. Mamm Genome 2011; 22:556-62. [PMID: 21732193 PMCID: PMC3179527 DOI: 10.1007/s00335-011-9344-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2011] [Accepted: 06/08/2011] [Indexed: 10/18/2022]
Abstract
Iron homeostasis is crucial to many biological functions in nearly all organisms, with roles ranging from oxygen transport to immune function. Disruption of iron homeostasis may result in iron overload or iron deficiency. Iron deficiency may have severe consequences, including anemia or changes in immune or neurotransmitter systems. Here we report on the variability of phenotypic iron tissue loss and splenomegaly and the associated quantitative trait loci (QTLs), polymorphic areas in the mouse genome that may contain one or more genes that play a role in spleen iron concentration or spleen weight under each dietary treatment. Mice from 26 BXD/Ty recombinant inbred strains, including the parent C57BL/6 and DBA/2 strains, were randomly assigned to adequate iron or iron-deficient diets at weaning. After 120 days, splenomegaly was measured by spleen weight, and spleen iron was assessed using a modified spectrophotometry technique. QTL analyses and gene expression comparisons were then conducted using the WebQTL GeneNetwork. We observed wide, genetic-based variability in splenomegaly and spleen iron loss in BXD/Ty recombinant inbred strains fed an iron-deficient diet. Moreover, we identified several suggestive QTLs. Matching our QTLs with gene expression data from the spleen revealed candidate genes. Our work shows that individual differences in splenomegaly response to iron deficiency are influenced at least partly by genetic constitution. We propose mechanistic hypotheses by which splenomegaly may result from iron deficiency.
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Affiliation(s)
- Jennifer N. Gibson
- Department of Biobehavioral Health, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Leslie C. Jellen
- Department of Biobehavioral Health, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Erica L. Unger
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Grant Morahan
- Centre for Diabetes Research, The Western Australia Institute for Medical Research, The University of Western Australia, Perth, WA Australia
| | - Munish Mehta
- Centre for Diabetes Research, The Western Australia Institute for Medical Research, The University of Western Australia, Perth, WA Australia
| | | | | | - Lu Lu
- Department of Anatomy and Neurobiology, University of Tennessee Health Sciences Center, Memphis, TN 38163, USA
| | - Byron C. Jones
- Department of Biobehavioral Health, The Pennsylvania State University, University Park, PA, 16802, USA
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40
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Bartzokis G, Lu PH, Tingus K, Peters DG, Amar CP, Tishler TA, Finn JP, Villablanca P, Altshuler LL, Mintz J, Neely E, Connor JR. Gender and iron genes may modify associations between brain iron and memory in healthy aging. Neuropsychopharmacology 2011; 36:1375-84. [PMID: 21389980 PMCID: PMC3096807 DOI: 10.1038/npp.2011.22] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Brain iron increases with age and is abnormally elevated early in the disease process in several neurodegenerative disorders that impact memory including Alzheimer's disease (AD). Higher brain iron levels are associated with male gender and presence of highly prevalent allelic variants in genes encoding for iron metabolism proteins (hemochromatosis H63D (HFE H63D) and transferrin C2 (TfC2)). In this study, we examined whether in healthy older individuals memory performance is associated with increased brain iron, and whether gender and gene variant carrier (IRON+) vs noncarrier (IRON-) status (for HFE H63D/TfC2) modify the associations. Tissue iron deposited in ferritin molecules can be measured in vivo with magnetic resonance imaging utilizing the field-dependent relaxation rate increase (FDRI) method. FDRI was assessed in hippocampus, basal ganglia, and white matter, and IRON+ vs IRON- status was determined in a cohort of 63 healthy older individuals. Three cognitive domains were assessed: verbal memory (delayed recall), working memory/attention, and processing speed. Independent of gene status, worse verbal-memory performance was associated with higher hippocampal iron in men (r=-0.50, p=0.003) but not in women. Independent of gender, worse verbal working memory performance was associated with higher basal ganglia iron in IRON- group (r=-0.49, p=0.005) but not in the IRON+ group. Between-group interactions (p=0.006) were noted for both of these associations. No significant associations with white matter or processing speed were observed. The results suggest that in specific subgroups of healthy older individuals, higher accumulations of iron in vulnerable gray matter regions may adversely impact memory functions and could represent a risk factor for accelerated cognitive decline. Combining genetic and MRI biomarkers may provide opportunities to design primary prevention clinical trials that target high-risk groups.
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Affiliation(s)
- George Bartzokis
- Department of Psychiatry and Biobehavioral Sciences, The David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-6968, USA.
| | - Po H Lu
- Department of Neurology, The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Kathleen Tingus
- Department of Neurology, The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Douglas G Peters
- Department of Psychiatry and Biobehavioral Sciences, The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA,Department of Psychiatry, Greater Los Angeles VA Healthcare System, Los Angeles, CA, USA
| | - Chetan P Amar
- Department of Psychiatry and Biobehavioral Sciences, The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA,Department of Psychiatry, Greater Los Angeles VA Healthcare System, Los Angeles, CA, USA
| | - Todd A Tishler
- Department of Psychiatry and Biobehavioral Sciences, The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA,Department of Psychiatry, Greater Los Angeles VA Healthcare System, Los Angeles, CA, USA
| | - J Paul Finn
- Department of Radiology, The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Pablo Villablanca
- Department of Radiology, The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Lori L Altshuler
- Department of Psychiatry and Biobehavioral Sciences, The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Jim Mintz
- Department of Epidemiology and Biostatistics, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Elizabeth Neely
- Department of Neurosurgery, Penn State Hershey Medical Center, Hershey, PA, USA
| | - James R Connor
- Department of Neurosurgery, Penn State Hershey Medical Center, Hershey, PA, USA
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McLaren CE, Garner CP, Constantine CC, McLachlan S, Vulpe CD, Snively BM, Gordeuk VR, Nickerson DA, Cook JD, Leiendecker-Foster C, Beckman KB, Eckfeldt JH, Barcellos LF, Murray JA, Adams PC, Acton RT, Killeen AA, McLaren GD. Genome-wide association study identifies genetic loci associated with iron deficiency. PLoS One 2011; 6:e17390. [PMID: 21483845 PMCID: PMC3069025 DOI: 10.1371/journal.pone.0017390] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 02/02/2011] [Indexed: 12/27/2022] Open
Abstract
The existence of multiple inherited disorders of iron metabolism in man, rodents and other vertebrates suggests genetic contributions to iron deficiency. To identify new genomic locations associated with iron deficiency, a genome-wide association study (GWAS) was performed using DNA collected from white men aged≥25 y and women≥50 y in the Hemochromatosis and Iron Overload Screening (HEIRS) Study with serum ferritin (SF)≤12 µg/L (cases) and iron replete controls (SF>100 µg/L in men, SF>50 µg/L in women). Regression analysis was used to examine the association between case-control status (336 cases, 343 controls) and quantitative serum iron measures and 331,060 single nucleotide polymorphism (SNP) genotypes, with replication analyses performed in a sample of 71 cases and 161 controls from a population of white male and female veterans screened at a US Veterans Affairs (VA) medical center. Five SNPs identified in the GWAS met genome-wide statistical significance for association with at least one iron measure, rs2698530 on chr. 2p14; rs3811647 on chr. 3q22, a known SNP in the transferrin (TF) gene region; rs1800562 on chr. 6p22, the C282Y mutation in the HFE gene; rs7787204 on chr. 7p21; and rs987710 on chr. 22q11 (GWAS observed P<1.51×10(-7) for all). An association between total iron binding capacity and SNP rs3811647 in the TF gene (GWAS observed P=7.0×10(-9), corrected P=0.012) was replicated within the VA samples (observed P=0.012). Associations with the C282Y mutation in the HFE gene also were replicated. The joint analysis of the HEIRS and VA samples revealed strong associations between rs2698530 on chr. 2p14 and iron status outcomes. These results confirm a previously-described TF polymorphism and implicate one potential new locus as a target for gene identification.
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Affiliation(s)
- Christine E McLaren
- Department of Epidemiology, University of California Irvine, Irvine, California, United States of America.
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42
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Benyamin B, Montgomery GW, Martin NG, Whitfield JB. Transferrin saturation and mortality. Clin Chem 2011; 57:921-3; author reply 923. [PMID: 21343418 DOI: 10.1373/clinchem.2011.162784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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43
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Pichler I, Minelli C, Sanna S, Tanaka T, Schwienbacher C, Naitza S, Porcu E, Pattaro C, Busonero F, Zanon A, Maschio A, Melville SA, Grazia Piras M, Longo DL, Guralnik J, Hernandez D, Bandinelli S, Aigner E, Murphy AT, Wroblewski V, Marroni F, Theurl I, Gnewuch C, Schadt E, Mitterer M, Schlessinger D, Ferrucci L, Witcher DR, Hicks AA, Weiss G, Uda M, Pramstaller PP. Identification of a common variant in the TFR2 gene implicated in the physiological regulation of serum iron levels. Hum Mol Genet 2010; 20:1232-40. [PMID: 21208937 DOI: 10.1093/hmg/ddq552] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The genetic determinants of variation in iron status are actively sought, but remain incompletely understood. Meta-analysis of two genome-wide association (GWA) studies and replication in three independent cohorts was performed to identify genetic loci associated in the general population with serum levels of iron and markers of iron status, including transferrin, ferritin, soluble transferrin receptor (sTfR) and sTfR-ferritin index. We identified and replicated a novel association of a common variant in the type-2 transferrin receptor (TFR2) gene with iron levels, with effect sizes highly consistent across samples. In addition, we identified and replicated an association between the HFE locus and ferritin and confirmed previously reported associations with the TF, TMPRSS6 and HFE genes. The five replicated variants were tested for association with expression levels of the corresponding genes in a publicly available data set of human liver samples, and nominally statistically significant expression differences by genotype were observed for all genes, although only rs3811647 in the TF gene survived the Bonferroni correction for multiple testing. In addition, we measured for the first time the effects of the common variant in TMPRSS6, rs4820268, on hepcidin mRNA in peripheral blood (n = 83 individuals) and on hepcidin levels in urine (n = 529) and observed an association in the same direction, though only borderline significant. These functional findings require confirmation in further studies with larger sample sizes, but they suggest that common variants in TMPRSS6 could modify the hepcidin-iron feedback loop in clinically unaffected individuals, thus making them more susceptible to imbalances of iron homeostasis.
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Affiliation(s)
- Irene Pichler
- Institute of Genetic Medicine, European Academy Bozen/Bolzano, 39100 Bolzano, Italy
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44
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McLachlan S, Lee SM, Steele TM, Hawthorne PL, Zapala MA, Eskin E, Schork NJ, Anderson GJ, Vulpe CD. In silico QTL mapping of basal liver iron levels in inbred mouse strains. Physiol Genomics 2010; 43:136-47. [PMID: 21062905 DOI: 10.1152/physiolgenomics.00025.2010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Both iron deficiency and iron excess are detrimental in many organisms, and previous studies in both mice and humans suggest that genetic variation may influence iron status in mammals. However, these genetic factors are not well defined. To address this issue, we measured basal liver iron levels in 18 inbred strains of mice of both sexes on a defined iron diet and found ∼4-fold variation in liver iron in males (lowest 153 μg/g, highest 661 μg/g) and ∼3-fold variation in females (lowest 222 μg/g, highest 658 μg/g). We carried out a genome-wide association mapping to identify haplotypes underlying differences in liver iron and three other related traits (copper and zinc liver levels, and plasma diferric transferrin levels) in a subset of 14 inbred strains for which genotype information was available. We identified two putative quantitative trait loci (QTL) that contain genes with a known role in iron metabolism: Eif2ak1 and Igf2r. We also identified four putative QTL that reside in previously identified iron-related QTL and 22 novel putative QTL. The most promising putative QTL include a 0.22 Mb region on Chromosome 7 and a 0.32 Mb region on Chromosome 11 that both contain only one candidate gene, Adam12 and Gria1, respectively. Identified putative QTL are good candidates for further refinement and subsequent functional studies.
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Affiliation(s)
- Stela McLachlan
- Department of Nutritional Science and Toxicology, University of California Berkeley, Berkeley, CA 94720, USA
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45
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Barton JC, Clayborn Barton J, Acton RT. Longer survival associated with HLA-A*03, B*14 among 212 hemochromatosis probands with HFE C282Y homozygosity and HLA-A and -B typing and haplotyping1. Eur J Haematol 2010; 85:439-47. [DOI: 10.1111/j.1600-0609.2010.01511.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Pardo Silva MC, Njajou OT, Alizadeh BZ, Hofman A, Witteman JCM, van Duijn CM, Janssens ACJW. HFE gene mutations increase the risk of coronary heart disease in women. Eur J Epidemiol 2010; 25:643-9. [PMID: 20640879 PMCID: PMC2931632 DOI: 10.1007/s10654-010-9489-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2009] [Accepted: 07/05/2010] [Indexed: 01/14/2023]
Abstract
The purpose of the present study is to examine HFE gene mutations in relation to newly diagnosed (incident) coronary heart disease (CHD). In a population-based follow-up study of 7,983 individuals aged 55 years and older, we compared the risk of incident CHD between HFE carriers and non-carriers, overall and stratified by sex and smoking status. HFE mutations were significantly associated with an increased risk of incident CHD in women but not in men (hazard ratio [HR] for women = 1.7, 95% confidence interval [CI] 1.2-2.4 versus HR for men = 0.9, 95% CI 0.7-1.2). This increased CHD risk associated with HFE mutations in women was statistically significant in never smokers (HR = 1.8, 95% CI 1.1-2.8) and current smokers (HR = 3.1, 95% CI 1.4-7.1), but not in former smokers (HR = 1.3, 95% CI 0.7-2.4). HFE mutations are associated with increased risk of incident CHD in women.
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Affiliation(s)
- M. Carolina Pardo Silva
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, P. O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Omer T. Njajou
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, P. O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Behrooz Z. Alizadeh
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, P. O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Albert Hofman
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, P. O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Jacqueline C. M. Witteman
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, P. O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - Cornelia M. van Duijn
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, P. O. Box 2040, 3000 CA Rotterdam, The Netherlands
| | - A. Cecile J. W. Janssens
- Department of Epidemiology, Erasmus University Medical Center Rotterdam, P. O. Box 2040, 3000 CA Rotterdam, The Netherlands
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47
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Factors influencing disease phenotype and penetrance in HFE haemochromatosis. Hum Genet 2010; 128:233-48. [DOI: 10.1007/s00439-010-0852-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 06/16/2010] [Indexed: 01/24/2023]
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48
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HFE genotype and iron metabolism in Chinese patients with myelodysplastic syndromes and aplastic anemia. Ann Hematol 2010; 89:1249-53. [PMID: 20563578 DOI: 10.1007/s00277-010-1016-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Accepted: 06/10/2010] [Indexed: 01/31/2023]
Abstract
The incidence of HFE gene mutations in myelodysplastic syndrome (MDS) cases remains controversial. In this study, we examined the HFE C282Y and H63D mutations in 271 Chinese patients with MDS, 402 with aplastic anemia (AA) and 1,615 healthy controls by polymerase chain reaction-restriction fragment length polymorphism in combination with DNA sequencing. No C282Y mutations were observed in the entire cohort. The distribution of H63D heterozygous and homozygous genotypes was not significantly different between the AA cases and the controls (9.7% versus 10.2%, 0.25% versus 0.24%, respectively). While the H63D heterozygous genotype in MDS patients was significantly lower than that in the controls (4.1% versus 10.2%, p = 0.002), the H63D homozygous genotype was not detected in the MDS patients. The results suggest that HFE gene mutations are not common genetic factors in Chinese patients with MDS and AA. We also compared iron metabolic parameters, including serum ferritin, serum iron, and transferrin saturation values, between HFE mutant and HFE wild-type groups in the absence of transfusion iron overload, but no significant difference was found in either MDS or AA patients except that the level of serum iron in AA patients was significantly higher in mutant carriers than in those with wild-type HFE (p = 0.011). Similarly, there was no significant difference between HFE mutant and HFE wild-type MDS and AA patients in clinical indices such as alanine aminotransferase, aspartate aminotransferase, fasting blood sugar values, and electrocardiogram. The results suggest that H63D mutations may not have clinical significance in Chinese patients with MDS and AA.
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49
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Casgrain A, Collings R, Harvey LJ, Boza JJ, Fairweather-Tait SJ. Micronutrient bioavailability research priorities. Am J Clin Nutr 2010; 91:1423S-1429S. [PMID: 20200267 DOI: 10.3945/ajcn.2010.28674a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A micronutrient bioavailability workshop, which involved international experts and members of the scientific community and the food industry, with interactive breakout sessions based on synectics principles, was organized by the International Life Sciences Institute Europe Addition of Nutrients to Food Task Force and the European Commission Network of Excellence European Micronutrient Recommendations Aligned. After presentations by experts, a series of "challenge statements" was discussed. The aim was to address topical issues, in particular those that linked bioavailability with the derivation of micronutrient requirements and dietary recommendations, to identify gaps in knowledge and to consider research priorities. Several generic research priorities were identified, including improving the quality of dietary surveys/food composition tables, the need for more metabolic studies that use stable isotopes and high-quality longer-term interventions, and the development of multifactorial mathematical models. Among the common recurrent factors identified as important were polymorphisms/genotype, consideration of the whole diet, chemical form of the micronutrient, and the determination of physiologic requirements. The involvement of all participants in the structured discussions ensured a broad overview of current knowledge, state-of-the-art research, and consideration of priorities for future research.
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Affiliation(s)
- Amélie Casgrain
- School of Medicine, Health Policy and Practice, University of East Anglia, Norwich, United Kingdom
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50
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Abstract
The genetic architecture of a disease determines the epidemiological methods for its examination. Recently, Bodmer and Bonilla suggested that moderately strong, moderately rare variants contribute substantially to the genetic population attributable risk (PAR) of common diseases. In the first part of this communication, I provide a concise reconstruction of their deliberation. Variants contributing to human disease can be identified by linkage or by association tests. Risch and Merikangas analyzed the power of these tests by comparing the affected sib-pair linkage test (ASP) and the transmission disequilibrium association test (TDT). In the second part of this paper, I give an accessible reconstruction of this comparison and derive simple approximations in the low allele frequency range, directly showing that the linkage test is much more sensitive to a decrease of frequency or effect size. In the third part, I analyze a disease model whose genetic architecture is proportional to Kimura's infinite sites model. The relation between a variant's selection coefficient and its effect size in disease generation is assumed to be simple, and the number of contributing genetic variants is determined by the sum of their approximative PAR contributions. An association test (TDT) is finally applied to this disease model. For different ranges of effect size and allele frequency, I derive the minimal sample size necessary to detect at least one contributing variant. It turns out that, although the majority of contributing variants is not accessible with realistic sample sizes, a minimum of sample size may be given for moderately strong variants in the 1% frequency range.
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Affiliation(s)
- Konrad Oexle
- Institute of Human Genetics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
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