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Levaillant L, Bouhours-Nouet N, Illouz F, Amsellem Jager J, Bachelot A, Barat P, Baron S, Bensignor C, Brac De La Perriere A, Braik Djellas Y, Caillot M, Caldagues E, Campas MN, Caquard M, Cartault A, Cheignon J, Decrequy A, Delemer B, Dieckmann K, Donzeau A, Doye E, Fradin M, Gaudillière M, Gatelais F, Gorce M, Hazart I, Houcinat N, Houdon L, Ister-Salome M, Jozwiak L, Jeannoel P, Labarthe F, Lacombe D, Lambert AS, Lefevre C, Leheup B, Leroy C, Maisonneuve B, Marchand I, Marquant E, Muszlak M, Pantalone L, Pochelu S, Quelin C, Radet C, Renoult-Pierre P, Reynaud R, Rouleau S, Teinturier C, Thevenon J, Turlotte C, Valle A, Vierge M, Villanueva C, Ziegler A, Dieu X, Bouzamondo N, Rodien P, Prunier-Mirebeau D, Coutant R. The Severity of Congenital Hypothyroidism With Gland-In-Situ Predicts Molecular Yield by Targeted Next-Generation Sequencing. J Clin Endocrinol Metab 2023; 108:e779-e788. [PMID: 36884306 PMCID: PMC10438870 DOI: 10.1210/clinem/dgad119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 02/07/2023] [Accepted: 02/23/2023] [Indexed: 03/09/2023]
Abstract
INTRODUCTION Congenital hypothyroidism with gland-in-situ (CH-GIS) is usually attributed to mutations in the genes involved in thyroid hormone production. The diagnostic yield of targeted next-generation sequencing (NGS) varied widely between studies. We hypothesized that the molecular yield of targeted NGS would depend on the severity of CH. METHODS Targeted NGS was performed in 103 CH-GIS patients from the French national screening program referred to the Reference Center for Rare Thyroid Diseases of Angers University Hospital. The custom targeted NGS panel contained 48 genes. Cases were classified as solved or probably solved depending on the known inheritance of the gene, the classification of the variants according to the American College of Medical Genetics and Genomics, the familial segregation, and published functional studies. Thyroid-stimulating hormone at CH screening and at diagnosis (TSHsc and TSHdg) and free T4 at diagnosis (FT4dg) were recorded. RESULTS NGS identified 95 variants in 10 genes in 73 of the 103 patients, resulting in 25 solved cases and 18 probably solved cases. They were mainly due to mutations in the TG (n = 20) and TPO (n = 15) genes. The molecular yield was, respectively, 73% and 25% if TSHsc was ≥ and < 80 mUI/L, 60% and 30% if TSHdg was ≥ and < 100 mUI/L, and 69% and 29% if FT4dg was ≤ and > 5 pmol/L. CONCLUSION NGS in patients with CH-GIS in France found a molecular explanation in 42% of the cases, increasing to 70% when TSHsc was ≥ 80 mUI/L or FT4dg was ≤ 5 pmol/L.
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Affiliation(s)
- Lucie Levaillant
- Department of Pediatric Endocrinology and Diabetology, University Hospital of Angers, 49000 Angers, France
- Reference Center for Rare Diseases of Thyroid and Hormone Receptivity, University Hospital of Angers, 49000 Angers, France
| | - Natacha Bouhours-Nouet
- Department of Pediatric Endocrinology and Diabetology, University Hospital of Angers, 49000 Angers, France
- Reference Center for Rare Diseases of Thyroid and Hormone Receptivity, University Hospital of Angers, 49000 Angers, France
| | - Frédéric Illouz
- Reference Center for Rare Diseases of Thyroid and Hormone Receptivity, University Hospital of Angers, 49000 Angers, France
- Department of Endocrinology, Diabetes and Nutrition, University Hospital of Angers, 49000 Angers, France
| | - Jessica Amsellem Jager
- Department of Pediatric Endocrinology and Diabetology, University Hospital of Angers, 49000 Angers, France
- Reference Center for Rare Diseases of Thyroid and Hormone Receptivity, University Hospital of Angers, 49000 Angers, France
| | - Anne Bachelot
- Department of Endocrinology and Reproductive Medicine, Hôpital Pitié-Salpêtrière, ICAN, 75651 Paris, France
| | - Pascal Barat
- Pediatric Endocrinology, CHU de Bordeaux, 33000 Bordeaux, France
| | - Sabine Baron
- Pediatrics Department, CHU Nantes, 44000 Nantes, France
| | | | - Aude Brac De La Perriere
- Hospices Civils de Lyon, Hôpital Femme Mère Enfant, Service d'Endocrinologie Pédiatrique, 69677 Bron, France
| | - Yasmine Braik Djellas
- Department of Endocrinology and Reproductive Medicine, Hôpital Pitié-Salpêtrière, ICAN, 75651 Paris, France
| | - Morgane Caillot
- Pediatrics Department, CH de Martigues, 13500 Martigues, France
| | | | | | | | - Audrey Cartault
- Endocrine, Genetics, Bone Diseases, and Paediatric Gynecology Unit, Children's Hospital, CHU Toulouse, 31059 Toulouse, France
| | - Julie Cheignon
- Department of Pediatric Endocrinology and Diabetology, University Hospital of Angers, 49000 Angers, France
| | - Anne Decrequy
- Department of Pediatric Endocrinology and Diabetology, University Hospital of Angers, 49000 Angers, France
| | - Brigitte Delemer
- Department of Endocrinology, Diabetes and Nutrition, CHU de Reims-Hôpital Robert-Debré, 51100 Reims, France
| | | | - Aurélie Donzeau
- Department of Pediatric Endocrinology and Diabetology, University Hospital of Angers, 49000 Angers, France
| | | | - Mélanie Fradin
- Service de Génétique, CLAD Ouest, CHU Rennes, 35200 Rennes, France
| | - Mélanie Gaudillière
- Hospices Civils de Lyon, Hôpital Femme Mère Enfant, Service d'Endocrinologie Pédiatrique, 69677 Bron, France
| | | | - Magali Gorce
- Service de Génétique, 49000 Angers Cedex 9, France
| | | | - Nada Houcinat
- CHU Dijon, Centre de référence maladies rares Anomalies du Développement et Syndromes Malformatifs, Centre de Génétique, FHU TRANSLAD, CHU Dijon Bourgogne 21000, France
| | - Laure Houdon
- Pediatric Diabetology, University Hospital, St Pierre de la Reunion 97410, France
| | | | - Lucie Jozwiak
- Pediatrics Department, CH de Roubaix, 59100 Roubaix, France
| | | | - Francois Labarthe
- Reference Center for Inborn Errors of Metabolism, Tours University Hospital, 37044 Tours, France
| | - Didier Lacombe
- Department of Medical Genetics, CHU Bordeaux INSERM U1211, Université de Bordeaux, 33076 Bordeaux, France
| | - Anne-Sophie Lambert
- AP-HP, Bicêtre Paris Saclay Hospital, DMU SEA, Endocrinology and Diabetes for Children, Le Kremlin Bicêtre 94270, France
| | - Christine Lefevre
- Pediatric Endocrinology, Jeanne de Flandre Hospital, 59037 Lille, France
| | - Bruno Leheup
- Service de Génétique clinique, Höpital Brabois, Centre Hospitalier Universitaire de Nancy, Nancy, Lorraine 54500, France
| | - Clara Leroy
- Service d'Endocrinologie et Maladies Métaboliques, Centre Hospitalier Régional Universitaire de Lille, Hôpital Huriez, 59037 Lille, France
| | | | - Isis Marchand
- Pediatrics Department, CHI de Créteil, 94010 Créteil, France
| | - Emeline Marquant
- Assistance-Publique des Hôpitaux de Marseille, Department of Pediatrics, Hôpital de la Timone Enfants, 13005 Marseille, France
| | | | | | - Sandra Pochelu
- Pediatric Endocrinology, CHU de Bordeaux, 33000 Bordeaux, France
| | - Chloé Quelin
- Service de Génétique, CLAD Ouest, CHU Rennes, 35200 Rennes, France
| | | | - Peggy Renoult-Pierre
- Service de Médecine Interne, Unité d'Endocrinologie Diabétologie et Nutrition, Centre Hospitalier Universitaire et Faculté de Médecine, Université de Tours, 37044 Tours, France
| | - Rachel Reynaud
- Assistance-Publique des Hôpitaux de Marseille, Department of Pediatrics, Hôpital de la Timone Enfants, 13005 Marseille, France
| | - Stéphanie Rouleau
- Department of Pediatric Endocrinology and Diabetology, University Hospital of Angers, 49000 Angers, France
| | - Cécile Teinturier
- AP-HP, Bicêtre Paris Saclay Hospital, DMU SEA, Endocrinology and Diabetes for Children, Le Kremlin Bicêtre 94270, France
| | - Julien Thevenon
- Inserm UMR 1231 GAD Team, Genetics of Developmental Anomalies, and FHU-TRANSLAD, CHU/Université de Bourgogne-Franche Comté, 21000 Dijon, France
| | | | - Aline Valle
- Pediatrics Department, CH de Douai, 59187 Douai, France
| | - Melody Vierge
- Assistance-Publique des Hôpitaux de Marseille, Department of Pediatrics, Hôpital de la Timone Enfants, 13005 Marseille, France
| | - Carine Villanueva
- Hospices Civils de Lyon, Hôpital Femme Mère Enfant, Service d'Endocrinologie Pédiatrique, 69677 Bron, France
| | | | - Xavier Dieu
- Reference Center for Rare Diseases of Thyroid and Hormone Receptivity, University Hospital of Angers, 49000 Angers, France
- Biochemistry and Molecular Biology Laboratory, University Hospital of Angers, 49000 Angers, France
| | - Nathalie Bouzamondo
- Reference Center for Rare Diseases of Thyroid and Hormone Receptivity, University Hospital of Angers, 49000 Angers, France
- Biochemistry and Molecular Biology Laboratory, University Hospital of Angers, 49000 Angers, France
| | - Patrice Rodien
- Reference Center for Rare Diseases of Thyroid and Hormone Receptivity, University Hospital of Angers, 49000 Angers, France
- Department of Endocrinology, Diabetes and Nutrition, University Hospital of Angers, 49000 Angers, France
| | - Delphine Prunier-Mirebeau
- Reference Center for Rare Diseases of Thyroid and Hormone Receptivity, University Hospital of Angers, 49000 Angers, France
- Biochemistry and Molecular Biology Laboratory, University Hospital of Angers, 49000 Angers, France
| | - Régis Coutant
- Department of Pediatric Endocrinology and Diabetology, University Hospital of Angers, 49000 Angers, France
- Reference Center for Rare Diseases of Thyroid and Hormone Receptivity, University Hospital of Angers, 49000 Angers, France
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Andersson M, Braegger CP. The Role of Iodine for Thyroid Function in Lactating Women and Infants. Endocr Rev 2022; 43:469-506. [PMID: 35552681 PMCID: PMC9113141 DOI: 10.1210/endrev/bnab029] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Indexed: 12/18/2022]
Abstract
Iodine is a micronutrient needed for the production of thyroid hormones, which regulate metabolism, growth, and development. Iodine deficiency or excess may alter the thyroid hormone synthesis. The potential effects on infant development depend on the degree, timing, and duration of exposure. The iodine requirement is particularly high during infancy because of elevated thyroid hormone turnover. Breastfed infants rely on iodine provided by human milk, but the iodine concentration in breast milk is determined by the maternal iodine intake. Diets in many countries cannot provide sufficient iodine, and deficiency is prevented by iodine fortification of salt. However, the coverage of iodized salt varies between countries. Epidemiological data suggest large differences in the iodine intake in lactating women, infants, and toddlers worldwide, ranging from deficient to excessive intake. In this review, we provide an overview of the current knowledge and recent advances in the understanding of iodine nutrition and its association with thyroid function in lactating women, infants, and toddlers. We discuss risk factors for iodine malnutrition and the impact of targeted intervention strategies on these vulnerable population groups. We highlight the importance of appropriate definitions of optimal iodine nutrition and the need for more data assessing the risk of mild iodine deficiency for thyroid disorders during the first 2 years in life.
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Affiliation(s)
- Maria Andersson
- Nutrition Research Unit, University Children's Hospital Zurich, CH-8032 Zürich, Switzerland
| | - Christian P Braegger
- Nutrition Research Unit, University Children's Hospital Zurich, CH-8032 Zürich, Switzerland
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Abstract
PURPOSE OF REVIEW Iodine deficiency is a global concern, and in recent years, there has been a significant improvement in the number of countries identified as being iodine-sufficient. This review considers the best strategies to ensure iodine sufficiency among breastfeeding women and their infants. RECENT FINDINGS Fortification strategies to improve iodine intake have been adequate for school-age children (SAC); however, often, iodine deficiency remains for breastfeeding women and their infants. Daily supplementation with iodine is not an ideal strategy to overcome deficiency. Countries defined as iodine-sufficient, but where pregnant and breastfeeding women have inadequate intake, should consider increasing salt iodine concentration, such that the median urinary iodine concentration of SAC can be up to 299 µg/L. This will ensure adequate intake for mothers and infants, without SAC being at risk thyroid dysfunction. Consensus is required for thresholds for iodine adequacy for breastfeeding women and infants.
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Geysels RC, Bernal Barquero CE, Martín M, Peyret V, Nocent M, Sobrero G, Muñoz L, Signorino M, Testa G, Castro RB, Masini-Repiso AM, Miras MB, Nicola JP. Silent but Not Harmless: A Synonymous SLC5A5 Gene Variant Leading to Dyshormonogenic Congenital Hypothyroidism. Front Endocrinol (Lausanne) 2022; 13:868891. [PMID: 35600585 PMCID: PMC9114739 DOI: 10.3389/fendo.2022.868891] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 03/23/2022] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Congenital iodide transport defect (ITD) is an uncommon cause of dyshormonogenic congenital hypothyroidism characterized by the absence of active iodide accumulation in the thyroid gland. ITD is an autosomal recessive disorder caused by loss-of-function variants in the sodium/iodide symporter (NIS)-coding SLC5A5 gene. OBJECTIVE We aimed to identify, and if so to functionally characterize, novel ITD-causing SLC5A5 gene variants in a cohort of five unrelated pediatric patients diagnosed with dyshormonogenic congenital hypothyroidism with minimal to absent 99mTc-pertechnetate accumulation in the thyroid gland. METHODS The coding region of the SLC5A5 gene was sequenced using Sanger sequencing. In silico analysis and functional in vitro characterization of a novel synonymous variant were performed. RESULTS Sanger sequencing revealed a novel homozygous synonymous SLC5A5 gene variant (c.1326A>C in exon 11). In silico analysis revealed that the c.1326A>C variant is potentially deleterious for NIS pre-mRNA splicing. The c.1326A>C variant was predicted to lie within a putative exonic splicing enhancer reducing the binding of splicing regulatory trans-acting protein SRSF5. Splicing minigene reporter assay revealed that c.1326A>C causes exon 11 or exon 11 and 12 skipping during NIS pre-mRNA splicing leading to the NIS pathogenic variants p.G415_P443del and p.G415Lfs*32, respectively. Significantly, the frameshift variant p.G415Lfs*32 is predicted to be subjected to degradation by nonsense-mediated decay. CONCLUSIONS We identified the first exonic synonymous SLC5A5 gene variant causing aberrant NIS pre-mRNA splicing, thus expanding the mutational landscape of the SLC5A5 gene leading to dyshormonogenic congenital hypothyroidism.
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Affiliation(s)
- Romina Celeste Geysels
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología - Consejo Nacional de Investigaciones Científicas y Técnicas (CIBICI-CONICET), Córdoba, Argentina
| | - Carlos Eduardo Bernal Barquero
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología - Consejo Nacional de Investigaciones Científicas y Técnicas (CIBICI-CONICET), Córdoba, Argentina
| | - Mariano Martín
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología - Consejo Nacional de Investigaciones Científicas y Técnicas (CIBICI-CONICET), Córdoba, Argentina
| | - Victoria Peyret
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología - Consejo Nacional de Investigaciones Científicas y Técnicas (CIBICI-CONICET), Córdoba, Argentina
| | - Martina Nocent
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología - Consejo Nacional de Investigaciones Científicas y Técnicas (CIBICI-CONICET), Córdoba, Argentina
| | - Gabriela Sobrero
- Programa Provincial de Pesquisa Neonatal, Servicio de Endocrinología, Hospital de Niños de la Santísima Trinidad de Córdoba, Córdoba, Argentina
| | - Liliana Muñoz
- Programa Provincial de Pesquisa Neonatal, Servicio de Endocrinología, Hospital de Niños de la Santísima Trinidad de Córdoba, Córdoba, Argentina
| | - Malvina Signorino
- Programa Provincial de Pesquisa Neonatal, Servicio de Endocrinología, Hospital de Niños de la Santísima Trinidad de Córdoba, Córdoba, Argentina
| | - Graciela Testa
- Programa Provincial de Pesquisa Neonatal, Servicio de Endocrinología, Hospital de Niños de la Santísima Trinidad de Córdoba, Córdoba, Argentina
| | | | - Ana María Masini-Repiso
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología - Consejo Nacional de Investigaciones Científicas y Técnicas (CIBICI-CONICET), Córdoba, Argentina
| | - Mirta Beatriz Miras
- Programa Provincial de Pesquisa Neonatal, Servicio de Endocrinología, Hospital de Niños de la Santísima Trinidad de Córdoba, Córdoba, Argentina
| | - Juan Pablo Nicola
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología - Consejo Nacional de Investigaciones Científicas y Técnicas (CIBICI-CONICET), Córdoba, Argentina
- *Correspondence: Juan Pablo Nicola,
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Martín M, Modenutti CP, Gil Rosas ML, Peyret V, Geysels RC, Bernal Barquero CE, Sobrero G, Muñoz L, Signorino M, Testa G, Miras MB, Masini-Repiso AM, Calcaterra NB, Coux G, Carrasco N, Martí MA, Nicola JP. A Novel SLC5A5 Variant Reveals the Crucial Role of Kinesin Light Chain 2 in Thyroid Hormonogenesis. J Clin Endocrinol Metab 2021; 106:1867-1881. [PMID: 33912899 PMCID: PMC8208674 DOI: 10.1210/clinem/dgab283] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Indexed: 12/17/2022]
Abstract
CONTEXT Iodide transport defect (ITD) (Online Mendelian Inheritance in Man No. 274400) is an uncommon cause of dyshormonogenic congenital hypothyroidism due to loss-of-function variants in the SLC5A5 gene, which encodes the sodium/iodide symporter (NIS), causing deficient iodide accumulation in thyroid follicular cells. OBJECTIVE This work aims to determine the molecular basis of a patient's ITD clinical phenotype. METHODS The propositus was diagnosed with dyshormonogenic congenital hypothyroidism with minimal 99mTc-pertechnetate accumulation in a eutopic thyroid gland. The propositus SLC5A5 gene was sequenced. Functional in vitro characterization of the novel NIS variant was performed. RESULTS Sanger sequencing revealed a novel homozygous missense p.G561E NIS variant. Mechanistically, the G561E substitution reduces iodide uptake, because targeting of G561E NIS to the plasma membrane is reduced. Biochemical analyses revealed that G561E impairs the recognition of an adjacent tryptophan-acidic motif by the kinesin-1 subunit kinesin light chain 2 (KLC2), interfering with NIS maturation beyond the endoplasmic reticulum, and reducing iodide accumulation. Structural bioinformatic analysis suggests that G561E shifts the equilibrium of the unstructured tryptophan-acidic motif toward a more structured conformation unrecognizable to KLC2. Consistently, knockdown of Klc2 causes defective NIS maturation and consequently decreases iodide accumulation in rat thyroid cells. Morpholino knockdown of klc2 reduces thyroid hormone synthesis in zebrafish larvae leading to a hypothyroid state as revealed by expression profiling of key genes related to the hypothalamic-pituitary-thyroid axis. CONCLUSION We report a novel NIS pathogenic variant associated with dyshormonogenic congenital hypothyroidism. Detailed molecular characterization of G561E NIS uncovered the significance of KLC2 in thyroid physiology.
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Affiliation(s)
- Mariano Martín
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA Córdoba, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología–Consejo Nacional de Investigaciones Científicas y Técnicas, X5000HUA Córdoba, Argentina
| | - Carlos Pablo Modenutti
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1428EGA Buenos Aires, Argentina
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales–Consejo Nacional de Investigaciones Científicas y Técnicas, C1428EGA Buenos Aires, Argentina
| | - Mauco Lucas Gil Rosas
- Departamento de Ciencias Biológicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, S2000EZP Rosario, Argentina
- Instituto de Biología Molecular y Celular de Rosario–Consejo Nacional de Investigaciones Científicas y Técnicas, S2000EZP Rosario, Argentina
| | - Victoria Peyret
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA Córdoba, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología–Consejo Nacional de Investigaciones Científicas y Técnicas, X5000HUA Córdoba, Argentina
| | - Romina Celeste Geysels
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA Córdoba, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología–Consejo Nacional de Investigaciones Científicas y Técnicas, X5000HUA Córdoba, Argentina
| | - Carlos Eduardo Bernal Barquero
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA Córdoba, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología–Consejo Nacional de Investigaciones Científicas y Técnicas, X5000HUA Córdoba, Argentina
| | - Gabriela Sobrero
- Programa Provincial de Pesquisa Neonatal, Hospital de Niños de la Santísima Trinidad de Córdoba, X5014AKK Córdoba, Argentina
| | - Liliana Muñoz
- Programa Provincial de Pesquisa Neonatal, Hospital de Niños de la Santísima Trinidad de Córdoba, X5014AKK Córdoba, Argentina
| | - Malvina Signorino
- Programa Provincial de Pesquisa Neonatal, Hospital de Niños de la Santísima Trinidad de Córdoba, X5014AKK Córdoba, Argentina
| | - Graciela Testa
- Programa Provincial de Pesquisa Neonatal, Hospital de Niños de la Santísima Trinidad de Córdoba, X5014AKK Córdoba, Argentina
| | - Mirta Beatriz Miras
- Programa Provincial de Pesquisa Neonatal, Hospital de Niños de la Santísima Trinidad de Córdoba, X5014AKK Córdoba, Argentina
| | - Ana María Masini-Repiso
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA Córdoba, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología–Consejo Nacional de Investigaciones Científicas y Técnicas, X5000HUA Córdoba, Argentina
| | - Nora Beatriz Calcaterra
- Departamento de Ciencias Biológicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, S2000EZP Rosario, Argentina
- Instituto de Biología Molecular y Celular de Rosario–Consejo Nacional de Investigaciones Científicas y Técnicas, S2000EZP Rosario, Argentina
| | - Gabriela Coux
- Departamento de Ciencias Biológicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, S2000EZP Rosario, Argentina
- Instituto de Biología Molecular y Celular de Rosario–Consejo Nacional de Investigaciones Científicas y Técnicas, S2000EZP Rosario, Argentina
| | - Nancy Carrasco
- Department of Cellular and Molecular Physiology, Yale School of Medicine, 06510 New Haven, Connecticut, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt School of Medicine, 37232 Nashville, Tennessee, USA
| | - Marcelo Adrián Martí
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1428EGA Buenos Aires, Argentina
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales–Consejo Nacional de Investigaciones Científicas y Técnicas, C1428EGA Buenos Aires, Argentina
| | - Juan Pablo Nicola
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA Córdoba, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología–Consejo Nacional de Investigaciones Científicas y Técnicas, X5000HUA Córdoba, Argentina
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Eriksen KG, Andersson M, Hunziker S, Zimmermann MB, Moore SE. Effects of an Iodine-Containing Prenatal Multiple Micronutrient on Maternal and Infant Iodine Status and Thyroid Function: A Randomized Trial in The Gambia. Thyroid 2020; 30:1355-1365. [PMID: 32183608 PMCID: PMC7482118 DOI: 10.1089/thy.2019.0789] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Background: Iodine supplementation is recommended to pregnant women in iodine-deficient populations, but the impact in moderate iodine deficiency is uncertain. We assessed the effect of an iodine-containing prenatal multiple micronutrient (MMN) supplement in a rural Gambian population at risk of moderate iodine deficiency. Materials and Methods: This study uses data and samples collected as a part of the randomized controlled trial Early Nutrition and Immune Development (ENID; ISRCTN49285450) conducted in Keneba, The Gambia. Pregnant women (<20 weeks gestation) were randomized to either a daily supplement of MMNs containing 300 μg of iodine or an iron and folic acid (FeFol) supplement. Randomization was double blinded (participants and investigators). The coprimary outcomes were maternal urinary iodine concentration (UIC) and serum thyroglobulin (Tg), assessed at baseline and at 30 weeks' gestation. Secondary outcomes were maternal serum thyrotropin (TSH), total triiodothyronine (TT3), total thyroxine (TT4) (assessed at baseline and at 30 weeks' gestation), breast milk iodine concentration (BMIC) (assessed at 8, 12, and 24 weeks postpartum), infant serum Tg (assessed at birth [cord], 12, and 24 weeks postpartum), and serum TSH (assessed at birth [cord]). The effect of supplementation was evaluated using mixed effects models. Results: A total of 875 pregnant women were enrolled between April 2010 and February 2015. In this secondary analysis, we included women from the MMN (n = 219) and FeFol (n = 219) arm of the ENID trial. At baseline, median (interquartile range or IQR) maternal UIC and Tg was 51 μg/L (33-82) and 22 μg/L (12-39), respectively, indicating moderate iodine deficiency. Maternal MMN supplement increased maternal UIC (p < 0.001), decreased maternal Tg (p < 0.001), and cord blood Tg (p < 0.001) compared with FeFol. Maternal thyroid function tests (TSH, TT3, TT4, and TT3/TT4 ratio) and BMIC did not differ according to maternal supplement group over the course of the study. Median (IQR) BMIC, maternal UIC, and infant Tg in the MMN group were 51 μg/L (35-72), 39 μg/L (25-64), and 87 μg/L (59-127), respectively, at 12 weeks postpartum, and did not differ between supplement groups. Conclusions: Supplementing moderately iodine-deficient women during pregnancy improved maternal iodine status and reduced Tg concentration. However, the effects were not attained postpartum and maternal and infant iodine nutrition remained inadequate during the first six months after birth. Consideration should be given to ensuring adequate maternal status through pregnancy and lactation in populations with moderate deficiency.
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Affiliation(s)
- Kamilla G. Eriksen
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
- Address correspondence to: Kamilla G. Eriksen, PhD, Department of Nutrition, Exercise and Sports, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg, Copenhagen, Denmark
| | - Maria Andersson
- Division of Gastroenterology and Nutrition, Children's Research Centre, University Children's Hospital Zurich, Zurich, Switzerland
| | - Sandra Hunziker
- Human Nutrition Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland
| | - Michael B. Zimmermann
- Human Nutrition Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland
| | - Sophie E. Moore
- Department of Women and Children's Health, King's College London, London, United Kingdom
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Farebrother J, Zimmermann MB, Assey V, Castro MC, Cherkaoui M, Fingerhut R, Jia Q, Jukic T, Makokha A, San Luis TO, Wegmüller R, Andersson M. Thyroglobulin Is Markedly Elevated in 6- to 24-Month-Old Infants at Both Low and High Iodine Intakes and Suggests a Narrow Optimal Iodine Intake Range. Thyroid 2019; 29:268-277. [PMID: 30648484 DOI: 10.1089/thy.2018.0321] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND In areas with incomplete salt iodization coverage, infants and children aged 6-24 months weaning from breast milk and receiving complementary foods are at risk of iodine deficiency. However, few data exist on the risk of excessive iodine intake in this age group. Thyroglobulin (Tg) is a sensitive marker of iodine intake in school-age children and adults and may be used to estimate the optimal iodine intake range in infancy. The aim of this study was to assess the association of low and high iodine intakes with Tg and thyroid function in weaning infants. METHODS This multicenter cross-sectional study recruited infants aged 6-24 months (n = 1543; Mage = 12.2 ± 4.6 months) receiving breast milk with complementary foods, from seven countries in areas with previously documented deficient, sufficient, or excessive iodine intake in schoolchildren or pregnant women. Urinary iodine concentration (UIC) and Tg, total thyroxine, and thyrotropin were measured using dried blood spot testing. RESULTS Median UIC ranged from 48 μg/L (interquartile range 31-79 μg/L) to 552 μg/L (interquartile range 272-987 μg/L) across the study sites. Median Tg using dried blood spot testing was high (>50 μg/L) at estimated habitual iodine intakes <50 μg/day and >230 μg/day. Prevalence of overt thyroid disorders was low (<3%). Yet, subclinical hyperthyroidism was observed in the countries with the lowest iodine intake. CONCLUSIONS Tg is a sensitive biomarker of iodine intake in 6- to 24-month-old infants and follows a U-shaped relationship with iodine intake, suggesting a relatively narrow optimal intake range. Infants with low iodine intake may be at increased risk of subclinical thyroid dysfunction. In population monitoring of iodine deficiency or excess, assessment of iodine status using UIC and Tg may be valuable in this young age group.
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Affiliation(s)
- Jessica Farebrother
- 1 Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Switzerland
| | - Michael B Zimmermann
- 1 Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Switzerland
- 2 Iodine Global Network, Ottawa, Ottawa, Canada
| | - Vincent Assey
- 2 Iodine Global Network, Ottawa, Ottawa, Canada
- 3 Nutrition Services Section, Preventive Services Department; Ministry of Health, Community Development, Gender, Elderly, and Children, Dar es Salaam, Tanzania
| | | | - Mohamed Cherkaoui
- 5 Faculté des Sciences Semlalia, Université Caddi Ayyed, Marrakech, Morocco
| | - Ralph Fingerhut
- 6 Swiss Newborn Screening Laboratory and Children's Research Center; University Children's Hospital Zurich, Zurich, Switzerland
| | - Qingzhen Jia
- 7 Shanxi Institute for Prevention and Treatment of Endemic Disease, Linfen, P.R. China
| | - Tomislav Jukic
- 8 Department of Nuclear Medicine and Oncology, Sestre Milosrdnice University Hospital Center and School of Medicine, University of Zagreb, Zagreb, Croatia
- 9 Faculty of Medicine Osijek, University Josip Juraj Strossmayer Osijek, Osijek, Croatia
| | - Anselimo Makokha
- 10 Department of Food Science, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Theofilo O San Luis
- 2 Iodine Global Network, Ottawa, Ottawa, Canada
- 11 St Luke's Medical Center, Quezon City, Manila, The Philippines
| | - Rita Wegmüller
- 12 Medical Research Council The Gambia, Keneba, The Gambia
| | - Maria Andersson
- 1 Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Switzerland
- 2 Iodine Global Network, Ottawa, Ottawa, Canada
- 13 Division of Gastroenterology and Nutrition; University Children's Hospital Zurich, Zurich, Switzerland
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8
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Watanabe Y, Sharwood E, Goodwin B, Creech MK, Hassan HY, Netea MG, Jaeger M, Dumitrescu A, Refetoff S, Huynh T, Weiss RE. A novel mutation in the TG gene (G2322S) causing congenital hypothyroidism in a Sudanese family: a case report. BMC MEDICAL GENETICS 2018; 19:69. [PMID: 29720101 PMCID: PMC5932782 DOI: 10.1186/s12881-018-0588-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 04/19/2018] [Indexed: 01/02/2023]
Abstract
Background Congenital hypothyroidism (CH) has an incidence of approximately 1:3000, but only 15% have mutations in the thyroid hormone synthesis pathways. Genetic analysis allows for the precise diagnosis. Case presentation A 3-week old girl presented with a large goiter, serum TSH > 100 mIU/L (reference range: 0.7–5.9 mIU/L); free T4 < 3.2 pmol/L (reference range: 8.7–16 pmol/L); thyroglobulin (TG) 101 μg/L. Thyroid Tc-99 m scan showed increased radiotracer uptake. One brother had CH and both affected siblings have been clinically and biochemically euthyroid on levothyroxine replacement. Another sibling had normal thyroid function. Both Sudanese parents reported non-consanguinity. Peripheral blood DNA from the proposita was subjected to whole exome sequencing (WES). WES identified a novel homozygous missense mutation of the TG gene: c.7021G > A, p.Gly2322Ser, which was subsequently confirmed by Sanger sequencing and present in one allele of both parents. DNA samples from 354 alleles in four Sudanese ethnic groups (Nilotes, Darfurians, Nuba, and Halfawien) failed to demonstrate the presence of the mutant allele. Haplotyping showed a 1.71 centiMorgans stretch of homozygosity in the TG locus suggesting that this mutation occurred identical by descent and the possibility of common ancestry of the parents. The mutation is located in the cholinesterase-like (ChEL) domain of TG. Conclusions A novel rare missense mutation in the TG gene was identified. The ChEL domain is critical for protein folding and patients with CH due to misfolded TG may present without low serum TG despite the TG gene mutations. Electronic supplementary material The online version of this article (10.1186/s12881-018-0588-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Y Watanabe
- Department of Medicine, University of Miami Miller School of Medicine, 1120 NW 14th St., Room 310F, Miami, FL, 33136, USA
| | - E Sharwood
- Department of Endocrinology and Diabetes, Lady Cilento Children's Hospital, Brisbane, QLD, Australia.,Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - B Goodwin
- Department of Endocrinology and Diabetes, Lady Cilento Children's Hospital, Brisbane, QLD, Australia.,Medical Imaging and Nuclear Medicine, Lady Cilento Children's Hospital, Brisbane, QLD, Australia
| | - M K Creech
- Department of Medicine, University of Miami Miller School of Medicine, 1120 NW 14th St., Room 310F, Miami, FL, 33136, USA
| | - H Y Hassan
- Banoon ART & Cytogenetics Centre, Bahrain Defence Force Hospital, West Riffa, Kingdom of Bahrain
| | - M G Netea
- Department of Internal Medicine, Radboud University Medical Cente, Nijmegen, The Netherlands
| | - M Jaeger
- Department of Internal Medicine, Radboud University Medical Cente, Nijmegen, The Netherlands
| | - A Dumitrescu
- Departments of Medicine, The University of Chicago, Chicago, IL, USA
| | - S Refetoff
- Departments of Medicine, Pediatrics and Genetics, The University of Chicago, Chicago, IL, USA
| | - T Huynh
- Department of Endocrinology and Diabetes, Lady Cilento Children's Hospital, Brisbane, QLD, Australia.,Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia.,Department of Chemical Pathology, Pathology Queensland, Herston, Brisbane, Queensland, Australia
| | - R E Weiss
- Department of Medicine, University of Miami Miller School of Medicine, 1120 NW 14th St., Room 310F, Miami, FL, 33136, USA.
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9
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Osei J, Andersson M, Reijden OVD, Dold S, Smuts CM, Baumgartner J. Breast-Milk Iodine Concentrations, Iodine Status, and Thyroid Function of Breastfed Infants Aged 2-4 Months and Their Mothers Residing in a South African Township. J Clin Res Pediatr Endocrinol 2016; 8:381-391. [PMID: 27217155 PMCID: PMC5197995 DOI: 10.4274/jcrpe.2720] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 05/22/2016] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE Lactating women and their infants are susceptible to iodine deficiency and iodine excess. In South Africa, no data exist on the iodine status and thyroid function of these vulnerable groups. METHODS In a cross-sectional study, urinary iodine concentrations (UIC), thyroid function, and breast-milk iodine concentrations (BMIC) were assessed in 100 lactating women from a South African township and their 2-4-month-old breastfed infants. Potential predictors of UIC, thyroid function, and BMIC, including household salt iodine concentrations (SIC) and maternal sodium excretion, were also investigated. RESULTS The median (25th-75th percentile) UIC was 373 (202-627) μg/L in infants and 118 (67-179) μg/L in mothers. Median household SIC was 44 (27-63) ppm. Household SIC and maternal urinary sodium excretion predicted UIC of lactating mothers. Median BMIC was 179 (126-269) μg/L. Age of infants, SIC, and maternal UIC predicted BMIC. In turn, infant age and BMIC predicted UIC of infants. Forty-two percent of SIC values were within the South African recommended salt iodine fortification level at production of 35-65 ppm, whilst 21% of SIC were >65 ppm. Thyroid-stimulating hormone, total thyroxine, and thyroglobulin concentrations in the dried whole blood spot specimens from the infants were 1.3 (0.8-1.9) mU/L, 128±33 mmol/L, and 77.1 (56.3-105.7) μg/L, respectively, and did not correlate with infant UIC or BMIC. CONCLUSION Our results suggest that the salt fortification program in South Africa provides adequate iodine to lactating women and indirectly to their infants via breast milk. However, monitoring of salt iodine content of the mandatory salt iodization program in South Africa is important to avoid over-iodization of salt.
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Affiliation(s)
- Jennifer Osei
- North-West University, Centre of Excellence for Nutrition, Potchefstroom, South Africa, Phone: +27 18 299 40 11 E-mail:
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10
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Chung HR. Adrenal and thyroid function in the fetus and preterm infant. KOREAN JOURNAL OF PEDIATRICS 2014; 57:425-33. [PMID: 25379042 PMCID: PMC4219944 DOI: 10.3345/kjp.2014.57.10.425] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 08/14/2014] [Indexed: 02/04/2023]
Abstract
Adrenal and thyroid hormones are essential for the regulation of intrauterine homeostasis, and for the timely differentiation and maturation of fetal organs. These hormones play complex roles during fetal life, and are believed to underlie the cellular communication that coordinates maternal-fetal interactions. They serve to modulate the functional adaptation for extrauterine life during the perinatal period. The pathophysiology of systemic vasopressor-resistant hypotension is associated with low levels of circulating cortisol, a result of immaturity of hypothalamic-pituitary-adrenal axis in preterm infants under stress. Over the past few decades, studies in preterm infants have shown abnormal clinical findings that suggest adrenal or thyroid dysfunction, yet the criteria used to diagnose adrenal insufficiency in preterm infants continue to be arbitrary. In addition, although hypothyroidism is frequently observed in extremely low gestational age infants, the benefits of thyroid hormone replacement therapy remain controversial. Screening methods for congenital hypothyroidism or congenital adrenal hyperplasia in the preterm neonate are inconclusive. Thus, further understanding of fetal and perinatal adrenal and thyroid function will provide an insight into the management of adrenal and thyroid function in the preterm infant.
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Affiliation(s)
- Hye Rim Chung
- Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea
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11
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Nicola JP, Nazar M, Serrano-Nascimento C, Goulart-Silva F, Sobrero G, Testa G, Nunes MT, Muñoz L, Miras M, Masini-Repiso AM. Iodide transport defect: functional characterization of a novel mutation in the Na+/I- symporter 5'-untranslated region in a patient with congenital hypothyroidism. J Clin Endocrinol Metab 2011; 96:E1100-7. [PMID: 21565787 DOI: 10.1210/jc.2011-0349] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
CONTEXT Iodide transport defect (ITD) is an autosomal recessive disorder caused by impaired Na(+)/I(-) symporter (NIS)-mediated active iodide accumulation into thyroid follicular cells. Clinical manifestations comprise a variable degree of congenital hypothyroidism and goiter, and low to absent radioiodide uptake, as determined by thyroid scintigraphy. Hereditary molecular defects in NIS have been shown to cause ITD. OBJECTIVE Our objective was to perform molecular studies on NIS in a patient with congenital hypothyroidism presenting a clinical ITD phenotype. DESIGN The genomic DNA encoding NIS was sequenced, and an in vitro functional study of a newly identified NIS mutation was performed. RESULTS The analysis revealed the presence of an undescribed homozygous C to T transition at nucleotide -54 (-54C>T) located in the 5'-untranslated region in the NIS sequence. Functional studies in vitro demonstrated that the mutation was associated with a substantial decrease in iodide uptake when transfected into Cos-7 cells. The mutation severely impaired NIS protein expression, although NIS mRNA levels remained similar to those in cells transfected with wild-type NIS, suggesting a translational deficiency elicited by the mutation. Polysome profile analysis demonstrated reduced levels of polyribosomes-associated mutant NIS mRNA, consistent with reduced translation efficiency. CONCLUSIONS We described a novel mutation in the 5'-untranslated region of the NIS gene in a newborn with congenital hypothyroidism bearing a clinical ITD phenotype. Functional evaluation of the molecular mechanism responsible for impaired NIS-mediated iodide concentration in thyroid cells indicated that the identified mutation reduces NIS translation efficiency with a subsequent decrease in protein expression and function.
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Affiliation(s)
- Juan Pablo Nicola
- Centro de Investigaciones en Bioquímica Clínica e Inmunología-Consejo Nacional de Investigaciones Científicas y Técnicas, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, 5000 Córdoba, Argentina
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12
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Melse-Boonstra A, Jaiswal N. Iodine deficiency in pregnancy, infancy and childhood and its consequences for brain development. Best Pract Res Clin Endocrinol Metab 2010; 24:29-38. [PMID: 20172468 DOI: 10.1016/j.beem.2009.09.002] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Iodine deficiency during foetal development and early childhood is associated with cognitive impairment. Randomised clinical studies in school-aged children encountered in the literature indicate that cognitive performance can be improved by iodine supplementation, but most studies suffer from methodological constraints. Tests to assess cognitive performance in the domains that are potentially affected by iodine deficiency need to be refined. Maternal iodine supplementation in areas of mild-to-moderate iodine deficiency may improve cognitive performance of the offspring, but randomised controlled studies with long-term outcomes are lacking. Studies in infants or young children have not been conducted. The best indicators for iodine deficiency in children are thyroid-stimulating hormone (TSH) in newborns and thyroglobulin (Tg) in older children. Urinary iodine may also be useful but only at the population level. Adequate salt iodisation will cover the requirements of infants and children as well as pregnant women. However, close monitoring remains essential.
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Affiliation(s)
- Alida Melse-Boonstra
- Division of Human Nutrition, Wageningen University, 6700 EV Wageningen, the Netherlands.
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Narumi S, Muroya K, Abe Y, Yasui M, Asakura Y, Adachi M, Hasegawa T. TSHR mutations as a cause of congenital hypothyroidism in Japan: a population-based genetic epidemiology study. J Clin Endocrinol Metab 2009; 94:1317-23. [PMID: 19158199 DOI: 10.1210/jc.2008-1767] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT The prevalence of congenital hypothyroidism (CH) associated with mutations in the TSH receptor gene (TSHR) has not been established. OBJECTIVE We examined the frequency of TSHR mutations among patients with permanent primary CH and in the general population in Japan. SUBJECTS AND METHODS We enrolled 102 patients with permanent primary CH [70 with "moderate to severe CH" (TSH, >or=10 mU/liter) and 32 with "mild CH" (TSH, 5-10 mU/liter)], who were identified through newborn screening among 353,000 newborns born in Kanagawa prefecture from October 1979 to June 2006. These subjects were tested for TSHR mutations by PCR-based direct sequencing. We further characterized molecular functions of identified mutant TSHRs in vitro. RESULTS We found three patients with moderate to severe CH who had biallelic mutations in TSHR and three patients with mild CH who had monoallelic mutations. Observed mutations included one previously characterized mutation (p.R450H) and three uncharacterized mutations (p.G132R, p.A204V, and p.D403N). In vitro experiments confirmed loss of functions of these four mutants. Among four mutations, p.R450H was particularly frequent: six of nine mutant alleles harbored p.R450H. All six alleles with p.R450H commonly carried a minor single nucleotide polymorphism, suggesting a founder effect. We estimated the prevalence of biallelic TSHR mutations to be 4.3% (three in 70) in Japanese patients with moderate to severe CH, and 1 in 118,000 (three in 353,000) in the general Japanese population. CONCLUSIONS In Japan, TSHR mutations are relatively common among patients with CH, and a founder mutation (p.R450H) accounts for about 70% of mutants.
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Affiliation(s)
- Satoshi Narumi
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
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