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Da DZ, Wang Y, Wang M, Long Z, Wang Q, Liu J. Congenital Hypothyroidism Patients With Thyroid Hormone Receptor Variants Are Not Rare: A Systematic Review. INQUIRY : A JOURNAL OF MEDICAL CARE ORGANIZATION, PROVISION AND FINANCING 2021; 58:469580211067943. [PMID: 34919466 PMCID: PMC8721697 DOI: 10.1177/00469580211067943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Primary congenital hypothyroidism (CH) is a common endocrine and metabolic disease. Various genetic factors, including the thyroid hormone receptor (TSHR), play an important role in CH. Aim To explore the occurrence of pathogenic TSHR variants in CH. Methods We searched published articles in PubMed, Web of Science, and Cochrane Library databases, from the establishment of the database to September 26, 2021. Studies with sequencing partial or full exons of TSHR in CH patients were included. Gene polymorphism was excluded. Results A total of 66 articles (44 case-control studies and 22 case reports) were selected from the database. Though case-control studies, we found the incidence of pathogenic TSHR variants were not rare (range from 0% to 30.6%) and varied greatly in different countries and race. The pathogenic genotypes varied in different regions. All the variants were “loss-of-function” mutations, in which the p.(Arg450His) variant was the most common variant. In addition, we analyzed the case reports and found that CH patients with a family genetic background expressed homozygous genotypes. Homozygotes had more obvious symptoms of hypothyroidism and higher risk of comorbidities than heterozygotes. Conclusion Pathogenic TSHR variants are not uncommon cause of the CH, especially in the Arabs. The role of TSHR gene detection in the treatment of children with CH needs to be further studied.
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Affiliation(s)
- Dong-Zhu Da
- Department of Breast-Thyroid-Vascular Surgery, Shanghai General Hospital, Shanghai, China.,Department of Breast and Thyroid Surgery, The Affiliated Huaian No.1 People's Hospital of Nanjing Medical University, Huaian, Jiangsu, China
| | - Ye Wang
- Department of Breast-Thyroid-Vascular Surgery, Shanghai General Hospital, Shanghai, China
| | - Min Wang
- Department of Breast-Thyroid-Vascular Surgery, Shanghai General Hospital, Shanghai, China
| | - Zhi Long
- Department of Pediatrics, Shanghai General Hospital, Shanghai, China
| | - Qian Wang
- Department of Pediatrics, Shanghai General Hospital, Shanghai, China
| | - Jun Liu
- Department of Breast-Thyroid-Vascular Surgery, Shanghai General Hospital, Shanghai, China
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Fang Y, Sun F, Zhang RJ, Zhang CR, Yan CY, Zhou Z, Zhang QY, Li L, Ying YX, Zhao SX, Liang J, Song HD. Mutation screening of the TSHR gene in 220 Chinese patients with congenital hypothyroidism. Clin Chim Acta 2019; 497:147-152. [PMID: 31356790 DOI: 10.1016/j.cca.2019.07.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 07/15/2019] [Accepted: 07/26/2019] [Indexed: 11/29/2022]
Abstract
BACKGROUND Defects in the human thyroid stimulating hormone receptor (TSHR) gene are reported to be one of the causes of congenital hypothyroidism (CH). We aimed to identify mutations in Chinese patients with CH and analyze the relationships between TSHR phenotypes and clinical phenotypes. METHODS 220 patients with primary CH were screened for TSHR mutations by performing next-generation sequencing. All the exons and exon-intron boundaries of TSHR were analyzed. The function of 8 mutants in TSHR were further investigated in vitro. RESULTS Among 220 patients with CH, 15 distinct TSHR mutations were identified in 13 patients (5.91%, 13/220, including our previous reported 110 patients, carried with 10 mutations in 8 patients). We found five distinct mutations in the additional cohort of 110 CH patients and identified 7 mutations (including a novel mutation, p.S567R) were loss-of-function mutations. CONCLUSION Our study indicated that the prevalence of TSHR mutations was 5.91% among studied Chinese patients with CH. One novel TSHR variant was found and four genetic alterations revealed important role of the Ile216, Ala275, Asn372, Ser567 residues in signaling.
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Affiliation(s)
- Ya Fang
- The Core Laboratory in Medical Center of Clinical Research, Department of Endocrinology, Shanghai Ninth People's Hospital, State Key Laboratory of Medical Genomics, Shanghai Jiao Tong University (SJTU), School of Medicine, Shanghai 200011, China
| | - Feng Sun
- The Core Laboratory in Medical Center of Clinical Research, Department of Endocrinology, Shanghai Ninth People's Hospital, State Key Laboratory of Medical Genomics, Shanghai Jiao Tong University (SJTU), School of Medicine, Shanghai 200011, China
| | - Rui-Jia Zhang
- The Core Laboratory in Medical Center of Clinical Research, Department of Endocrinology, Shanghai Ninth People's Hospital, State Key Laboratory of Medical Genomics, Shanghai Jiao Tong University (SJTU), School of Medicine, Shanghai 200011, China
| | - Chang-Run Zhang
- The Core Laboratory in Medical Center of Clinical Research, Department of Endocrinology, Shanghai Ninth People's Hospital, State Key Laboratory of Medical Genomics, Shanghai Jiao Tong University (SJTU), School of Medicine, Shanghai 200011, China
| | - Chen-Yan Yan
- The Core Laboratory in Medical Center of Clinical Research, Department of Endocrinology, Shanghai Ninth People's Hospital, State Key Laboratory of Medical Genomics, Shanghai Jiao Tong University (SJTU), School of Medicine, Shanghai 200011, China
| | - Zheng Zhou
- The Core Laboratory in Medical Center of Clinical Research, Department of Endocrinology, Shanghai Ninth People's Hospital, State Key Laboratory of Medical Genomics, Shanghai Jiao Tong University (SJTU), School of Medicine, Shanghai 200011, China
| | - Qian-Yue Zhang
- The Core Laboratory in Medical Center of Clinical Research, Department of Endocrinology, Shanghai Ninth People's Hospital, State Key Laboratory of Medical Genomics, Shanghai Jiao Tong University (SJTU), School of Medicine, Shanghai 200011, China
| | - Lu Li
- The Core Laboratory in Medical Center of Clinical Research, Department of Endocrinology, Shanghai Ninth People's Hospital, State Key Laboratory of Medical Genomics, Shanghai Jiao Tong University (SJTU), School of Medicine, Shanghai 200011, China
| | - Ying-Xia Ying
- The Core Laboratory in Medical Center of Clinical Research, Department of Endocrinology, Shanghai Ninth People's Hospital, State Key Laboratory of Medical Genomics, Shanghai Jiao Tong University (SJTU), School of Medicine, Shanghai 200011, China
| | - Shuang-Xia Zhao
- The Core Laboratory in Medical Center of Clinical Research, Department of Endocrinology, Shanghai Ninth People's Hospital, State Key Laboratory of Medical Genomics, Shanghai Jiao Tong University (SJTU), School of Medicine, Shanghai 200011, China
| | - Jun Liang
- Department of Endocrinology, The Central Hospital of Xuzhou Affiliated to Xuzhou Medical College, Xuzhou, Jiangsu Province 221109, China
| | - Huai-Dong Song
- The Core Laboratory in Medical Center of Clinical Research, Department of Endocrinology, Shanghai Ninth People's Hospital, State Key Laboratory of Medical Genomics, Shanghai Jiao Tong University (SJTU), School of Medicine, Shanghai 200011, China; Department of Endocrinology, The Central Hospital of Xuzhou Affiliated to Xuzhou Medical College, Xuzhou, Jiangsu Province 221109, China.
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Patel KA, Knight B, Aziz A, Babiker T, Tamar A, Findlay J, Cox S, Dimitropoulos I, Tysoe C, Panicker V, Vaidya B. Utility of systematic TSHR gene testing in adults with hyperthyroidism lacking overt autoimmunity and diffuse uptake on thyroid scintigraphy. Clin Endocrinol (Oxf) 2019; 90:328-333. [PMID: 30372544 PMCID: PMC6378592 DOI: 10.1111/cen.13892] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 10/24/2018] [Accepted: 10/24/2018] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Patients with hyperthyroidism lacking autoimmune features but showing diffuse uptake on thyroid scintigram can have either Graves' disease or germline activating TSH receptor (TSHR) mutation. It is important to identify patients with activating TSHR mutation due to treatment implication, but the overlapping clinical features with Graves' disease make it difficult to discriminate these two conditions without genetic testing. Our study aimed to assess the potential of systematic TSHR mutation screening in adults with hyperthyroidism, showing diffuse uptake on thyroid scintigraphy but absence of TSH receptor antibodies (TRAb) and clinical signs of autoimmunity. DESIGN A cross-sectional study of Caucasian adults with hyperthyroidism, managed at three endocrine centres in the South West, UK, from January 2006 to April 2017. METHODS We recruited 78 adult Caucasian patients with hyperthyroidism showing diffuse uptake on 99m Tc-pertechnetate thyroid scintigraphy but without TRAb and other autoimmune clinical features of Graves' disease (such as thyroid-associated ophthalmopathy or dermopathy). Genomic DNA of these patients was analysed for variants in the TSHR gene. RESULTS Genetic analysis identified 11 patients with four variants in TSHR [p.(Glu34Lys), p.(Asp36His), p.(Pro52Thr) and p.(Ile334Thr)]. None of these variants were pathogenic according to the American College of Medical Genetics and Genomics guideline. CONCLUSIONS Activating TSHR mutations are a rare cause of nonautoimmune adult hyperthyroidism. Our study does not support the routine genetic testing in adult patients with hyperthyroidism showing diffuse uptake on scintigraphy but negative TRAb and lacking extrathyroidal manifestations of Graves' disease.
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Affiliation(s)
- Kashyap A. Patel
- The Institute of Biomedical and Clinical ScienceUniversity of Exeter Medical SchoolExeterUK
- Department of Diabetes and EndocrinologyThe Royal Devon and Exeter NHS Foundation TrustExeterUK
| | - Bridget Knight
- The Institute of Biomedical and Clinical ScienceUniversity of Exeter Medical SchoolExeterUK
- NIHR Clinical Research Facility, R&D DepartmentThe Royal Devon and Exeter NHS Foundation trustExeterUK
| | - Aftab Aziz
- Department of Diabetes and EndocrinologyUniversity Hospitals Plymouth NHS TrustPlymouthUK
| | - Tarig Babiker
- Department of Diabetes and EndocrinologyUniversity Hospitals Plymouth NHS TrustPlymouthUK
| | - Avades Tamar
- Department of Diabetes and EndocrinologyThe Royal Devon and Exeter NHS Foundation TrustExeterUK
| | - Joanna Findlay
- NIHR Clinical Research Facility, R&D DepartmentThe Royal Devon and Exeter NHS Foundation trustExeterUK
| | - Sue Cox
- Department of Diabetes and Endocrinology, Torbay and South DevonNHS Foundation TrustTorbayUK
| | - Ioannis Dimitropoulos
- Department of Diabetes and EndocrinologyUniversity Hospitals Plymouth NHS TrustPlymouthUK
| | - Carolyn Tysoe
- Department of Molecular GeneticsThe Royal Devon and Exeter NHS Foundation TrustExeterUK
| | - Vijay Panicker
- Department of EndocrinologySir Charles Gairdner HospitalNedlandsWestern AustraliaAustralia
| | - Bijay Vaidya
- The Institute of Biomedical and Clinical ScienceUniversity of Exeter Medical SchoolExeterUK
- Department of Diabetes and EndocrinologyThe Royal Devon and Exeter NHS Foundation TrustExeterUK
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Abstract
Developmental anomalies of the thyroid gland, defined as thyroid dysgenesis, underlie the majority of cases of congenital hypothyroidism. Thyroid dysgenesis is predominantly a sporadic disorder although a reported familial enrichment, variation of incidence by ethnicity and the monogenic defects associated mainly with athyreosis or orthotopic thyroid hypoplasia, suggest a genetic contribution. Of note, the most common developmental anomaly, thyroid ectopy, remains unexplained. Ectopy may result from multiple genetic or epigenetic variants in the germline and/or at the somatic level. This review provides a brief overview of the monogenic defects in candidate genes that have been identified so far and of the syndromes which are known to be associated with thyroid dysgenesis.
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Affiliation(s)
- Rasha Abu-Khudir
- Endocrinology Service and Research Center, Sainte-Justine Hospital and Department of Pediatrics, University of Montreal, Montreal, H3T 1C5, Quebec, Canada; Chemistry Department, Biochemistry Division, Faculty of Science, Tanta University, Tanta, 31527, Egypt.
| | - Stéphanie Larrivée-Vanier
- Endocrinology Service and Research Center, Sainte-Justine Hospital and Department of Pediatrics, University of Montreal, Montreal, H3T 1C5, Quebec, Canada.
| | - Jonathan D Wasserman
- Division of Endocrinology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada.
| | - Johnny Deladoëy
- Endocrinology Service and Research Center, Sainte-Justine Hospital and Department of Pediatrics, University of Montreal, Montreal, H3T 1C5, Quebec, Canada.
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Abstract
Resistance to thyrotropin (RTSH) is broadly defined as reduced sensitivity of thyroid follicle cells to stimulation by biologically active TSH due to genetic defects. Affected individuals have elevated serum TSH in the absence of goiter, with the severity ranging from nongoitrous isolated hyperthyrotropinemia to severe congenital hypothyroidism with thyroid hypoplasia. Conceptually, defects leading to RTSH impair both aspects of TSH-mediated action, namely thyroid hormone synthesis and gland growth. These include inactivating mutations in the genes encoding the TSH receptor and the PAX8 transcription factor. A common third cause has been genetically mapped to a locus on chromosome 15, but the underlying pathophysiology has not yet been elucidated. This review provides a succinct overview of currently defined causes of nonsyndromic RTSH, their differential diagnoses (autoimmune; partial iodine organification defects; syndromic forms of RTSH) and implications for the clinical approach to patients with RTSH.
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Affiliation(s)
- Helmut Grasberger
- University of Michigan, 6504 MSRB I, 1150 West Medical Center Drive, Ann Arbor, MI 48109, USA.
| | - Samuel Refetoff
- The University of Chicago, MC3090, 5841 South Maryland Avenue, Chicago, IL 60637, USA.
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Park KJ, Park HK, Kim YJ, Lee KR, Park JH, Park JH, Park HD, Lee SY, Kim JW. DUOX2 Mutations Are Frequently Associated With Congenital Hypothyroidism in the Korean Population. Ann Lab Med 2017; 36:145-53. [PMID: 26709262 PMCID: PMC4713848 DOI: 10.3343/alm.2016.36.2.145] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Revised: 12/02/2015] [Accepted: 12/02/2015] [Indexed: 12/05/2022] Open
Abstract
Background Most cases with congenital hypothyroidism (CH) are usually sporadic, while about 20% of the cases are caused by genetic defects. Little information is available regarding the mutation incidence and genetic heterogeneity of CH in Koreans. We aimed to determine the mutation incidence of CH in newborn screenings (NBS) and to evaluate the frequency and spectrum of mutations underlying CH. Methods A total of 112 newborns with thyroid dysfunction were enrolled from 256,624 consecutive NBS. Furthermore, 58 outpatients with primary CH were added from an endocrine clinic. All coding exons of TSHR, PAX8, TPO, DUOX2, DUOXA2, and SCL5A5 were sequenced. Results The mutation incidence of CH was estimated to be 1 in 6,580 newborns. A total of 36 different mutations were identified in 53 cases. The overall mutation positive rate was 31%. The DUOX2 mutations were the most prevalent in both newborns and outpatients. Seven different recurrent mutations [p.G488R (n=13), p.A649E (n=3), p.R885Q (n=3), p.I1080T (n=2), and p.A1206T (n=2) in DUOX2; p.Y138X (n=9) in DUOXA2; and p.R450H (n=5) in TSHR) were identified as the mutations underlying CH. Conclusions The mutation incidence of CH was considerably higher than expected in the Korean newborn population. This study revealed seven different recurrent mutations underlying CH. We conclude that DUOX2 mutations are a frequent cause of CH in the Korean population.
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Affiliation(s)
- Kyoung-Jin Park
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, Korea
| | - Hyun-Kyung Park
- Department of Laboratory Medicine, Seoul Clinical Laboratories, Seoul Medical Science Institute, Seoul, Korea
| | - Young-Jin Kim
- Department of Laboratory Medicine, Seoul Clinical Laboratories, Seoul Medical Science Institute, Seoul, Korea
| | - Kyoung-Ryul Lee
- Department of Laboratory Medicine, Seoul Clinical Laboratories, Seoul Medical Science Institute, Seoul, Korea
| | - Jong-Ho Park
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, Korea
| | - June-Hee Park
- Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Korea
| | - Hyung-Doo Park
- Department of Laboratory Medicine & Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Soo-Youn Lee
- Department of Laboratory Medicine & Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jong-Won Kim
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, Korea.,Department of Laboratory Medicine & Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
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Picard C, Decrequy A, Guenet D, Bursztejn AC, Toledano D, Richard N, Kottler ML. Diagnosis and management of congenital hypothyroidism associated with pseudohypoparathyroidism. Horm Res Paediatr 2015; 83:111-7. [PMID: 25591844 DOI: 10.1159/000369492] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 10/29/2014] [Indexed: 11/19/2022] Open
Abstract
UNLABELLED Hypothyroidism is a particular condition observed in pseudohypoparathyroidism (PHP), a rare disorder characterized by parathyroid (PTH) resistance leading to hypocalcemia and hyperphosphatemia associated with a GNAS (guanine nucleotide-binding protein α-subunit) mutation (PHP1A) or epimutation (PHP1B). To determine the presence of hypothyroidism at birth we conducted a retrospective study in our cohort of patients presenting with either PHP1A (n = 116) or PHP1B (n = 99). We also investigated patients presenting at birth with congenital hypothyroidism (CH) and a eutopic thyroid gland for phosphocalcium abnormalities suggesting PTH resistance and PHP. Our study reveals CH as the earliest diagnostic clue for PHP1A, but not for PHP1B. We estimated the frequency of CH at birth to be between 8 and 34% in patients presenting with PHP1A. The elevation of phosphatemia and PTH concentration precedes hypocalcemia in PHP1A. Conversely, the frequency of PHP1A in patients presenting CH is dramatically low. This may be due to the low prevalence of PHP1A which remains unknown. CONCLUSIONS Subclinical and overt hypothyroidism can occur in PHP1A patients at birth many years before PTH resistance becomes clinically apparent. Although such cases appear to be rare, some pediatric patients with unexplained CH are likely to benefit from measuring calcium, phosphorus, and PTH for extended periods of time.
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Affiliation(s)
- Charlotte Picard
- Service de Génétique, Centre de Référence des Maladies Rares du Métabolisme du Calcium et du Phosphore, CHU de Caen, Caen, France
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Hasani-Ranjbar S, Jouyandeh Z, Amoli MM, Soltani A, Arzaghi SM. A patient with features of albright hereditory osteodystrophy and unusual neuropsychiatric findings without coding Gsalpha mutations. J Diabetes Metab Disord 2014; 13:56. [PMID: 24959527 PMCID: PMC4067066 DOI: 10.1186/2251-6581-13-56] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 04/10/2014] [Indexed: 11/10/2022]
Abstract
BACKGROUND Pseudohypoparathyroidism(PHP) is a heterogeneous group of rare metabolic disorders characterized by hypocalcemia and hyperphosphatemia resulting from PTH resistance. Different forms of PHP have been reported based on biochemical and clinical manifestation and genetic findings. Most of these forms are caused by defects in GNAS, an imprinted gene locus with multiple subunits. We reported a 12- year- old girl with unusual clinical manifestations of Pseudopseudohypoparathyroidism(PPHP). METHODS After clinical and biochemical evaluations, the patients' genomic DNA was isolated from peripheral blood leukocytes using salting out method. The whole coding sequences of GNAS gene including 13 exons were amplified by PCR. Quantitative PCR reactions were performed too. FINDINGS We described a 12- year- old girl with Albright Hereditory osteodystrophy (AHO) phenotype, poor school performance, some abnormal movements, TSH resistance with normal serum calcium and phosphorus levels and normal Gsα bioactivity with no mutation in GNAS exons. Unusual neuropsychiatric findings in this patient were compatible with Asperger syndrome. CONCLUSIONS According to our findings this patient could not be categorized in any of PHP subgroups. Identifying of such individuals may be useful to discover different genetic patterns in pseudohypoparathyroidism and pseudopseudohypoparathyroidism. It is important to identify patients in whom PHP is caused by novel GNAS mutations, as careful investigations of these findings will likely further our knowledge of this complex and this unique disorder. In addition this case presented with unusual neuropsychiatric findings which has not been reported up to now.
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Affiliation(s)
- Shirin Hasani-Ranjbar
- Obesity & Eating Habits Research Center, Endocrinology and metabolism Cellular & Molecular Science Institute, Endocrinology & Metabolism research institute, Tehran University of Medical Sciences, Tehran, Iran ; Endocrinology and Metabolism Research center, Endocrinology & Metabolism research institute, Tehran University of Medical Sciences, Tehran, Iran ; Endocrinology & Metabolism Research Institute, 5th Floor, Shariati Hospital, North Kargar Ave., Tehran 14114, Iran
| | - Zahra Jouyandeh
- Endocrinology and Metabolism Research center, Endocrinology & Metabolism research institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahsa Mohammad Amoli
- Endocrinology and Metabolism Research center, Endocrinology & Metabolism research institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Akbar Soltani
- Endocrinology and Metabolism Research center, Endocrinology & Metabolism research institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Seyed Masoud Arzaghi
- Endocrinology and Metabolism Research center, Endocrinology & Metabolism research institute, Tehran University of Medical Sciences, Tehran, Iran
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Abstract
The most frequent cause of congenital hypothyroidism is thyroid dysgenesis. Thyroid dysgenesis summarizes a spectrum of developmental abnormalities of the embryonic thyroid ranging from complete absence of the thyroid gland (athyreosis), to a normally located but too small thyroid (hypoplasia), or an abnormally located thyroid gland (ectopy). Although considered a sporadic disease, distinct genetic forms of isolated or syndromic thyroid dysgenesis have been described in recent years. However, genetics of thyroid dysgenesis (TD) are mostly not following simple Mendelian patterns, and beside monogenic, multigenic and epigenetic mechanisms need to be considered. The review will highlight the molecular mechanisms of thyroid organogenesis, clinical and genetic features of the different monogenetic forms of thyroid dysgenesis, the aspects relevant for diagnosis and counseling of affected families and current research strategies to get more insight into the non-Medelian mechanisms of normal and abnormal thyroid development.
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Affiliation(s)
- Gabor Szinnai
- Division of Paediatric Endocrinology and Diabetology, University Children's Hospital Basel UKBB, Spitalstrasse 33, CH-4031 Basel, Switzerland; Department of Biomedicine, University Basel, Spitalstrasse 33, CH-4031 Basel, Switzerland.
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Cassio A, Nicoletti A, Rizzello A, Zazzetta E, Bal M, Baldazzi L. Current loss-of-function mutations in the thyrotropin receptor gene: when to investigate, clinical effects, and treatment. J Clin Res Pediatr Endocrinol 2013; 5 Suppl 1:29-39. [PMID: 23154162 PMCID: PMC3608004 DOI: 10.4274/jcrpe.864] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Thyroid-stimulating hormone receptor (TSHR) loss-of-function (LOF) mutations lead to a wide spectrum of phenotypes, ranging from severe congenital hypothyroidism (CH) to mild euthyroid hyperthyrotropinemia. The degree of TSH resistance depends on the severity of the impairment of the receptor function caused by the mutation and on the number of mutated alleles In this review data about genotype-phenotype correlation and criteria for clinical work-up will be presented and discussed. Complete TSH resistance due to biallelic LOF TSHR mutations must be suspected in all patients with severe not syndromic CH and severe thyroid hypoplasia diagnosed at birth by neonatal screening. Partial forms of TSH resistance show a more heterogeneous hormonal and clinical pattern . In these cases TSH serum levels are above the upper limit of normal range for the age but with a very variable pattern, free thyroxine (T4) concentrations are within the normal range and thyroid size can be normal or hypoplastic at ultrasound scan. An early substitutive treatment with L-T4 must be mandatory in all patients with severe CH due to complete uncompensated TSH resistance diagnosed at birth by neonatal screening. The usefulness of substitutive treatment appears much more controversial inpatients with subclinical hypothyroidism due to partial TSH resistance in whom the increased TSH concentration should be able to compensate the mild functional impairment of the mutant receptor. Together with standard criteria we recommend also an accurate clinical work-up to select patients who are candidates for a LOF TSHR mutation.
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Affiliation(s)
- Alessandra Cassio
- Department of Gynaecologic, Obstetric and Paediatric Sciences, S Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
| | - Annalisa Nicoletti
- Department of Gynaecologic, Obstetric and Paediatric Sciences, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
| | - Angela Rizzello
- Department of Gynaecologic, Obstetric and Paediatric Sciences, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
| | - Emanuela Zazzetta
- Department of Gynaecologic, Obstetric and Paediatric Sciences, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
| | - Milva Bal
- Department of Gynaecologic, Obstetric and Paediatric Sciences, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
| | - Lilia Baldazzi
- Department of Gynaecologic, Obstetric and Paediatric Sciences, S.Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
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Lucas-Herald A, Bradley T, Hermanns P, Jones J, Attaie M, Thompson E, Pohlenz J, Donaldson M. Novel heterozygous thyrotropin receptor mutation presenting with neonatal hyperthyrotropinaemia, mild thyroid hypoplasia and absent uptake on radioisotope scan. J Pediatr Endocrinol Metab 2013; 26:583-6. [PMID: 23412867 DOI: 10.1515/jpem-2012-0308] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 01/16/2013] [Indexed: 11/15/2022]
Abstract
Hyperthyrotropinaemia [mildly elevated thyrotropin (TSH) with normal thyroxine (T4) levels] demands a full assessment, including clinical examination, thyroid imaging and, where indicated, molecular genetic investigations. A male infant, both of whose parents were on T4 treatment, was referred at age 57 days with mild but persistent TSH elevation (12.7 mU/L) and normal free T4 (19.6 pmol/L), following notification by the screening laboratory of a capillary TSH of 10.7 mU/L (reference range, 1.7-9.1 mU/L) on day 8. Assessment showed a venous free T4 level of 15 pmol/L, venous TSH of 20.9 mU/L, serum thyroglobulin of 63 μg/L (reference range, <50 μg/L), and negative thyroglobulin and thyroid peroxidase antibodies. Thyroid ultrasound showed a eutopic, slightly small gland with heterogeneous texture; however, there was no uptake on radioisotope scan. Molecular genetic studies demonstrated a novel missense heterozygous mutation in the TSH receptor (TSHR) gene (c.1169G>T;p.Cys390Phe) in the child, mother and maternal grandmother, but not in the father. The infant was treated with T4 but this was discontinued at age 3 years when repeat testing showed a free T4 of 16.7 pmol/L (reference range, 9-23 pmol/L) and TSH of 8.5 mU/L (reference range, 0.3-5.5 mU/L). A heterozygous TSHR mutation should be considered in the context of hyperthyrotropinaemia and reduced/absent uptake on radioisotope scan. Detection of this mutation has allowed our patient to discontinue T4 treatment for the moment, with a view to staying off treatment in the long-term.
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Affiliation(s)
- Angela Lucas-Herald
- Child Health Unit, School of Medicine, Royal Hospital for Sick Children, Glasgow G3 8SJ, UK
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Mansourian AR. Central dogma in thyroid dysfunction: a review on structure modification of TSHR as a cornerstone for thyroid abnormalities. Pak J Biol Sci 2011; 14:170-81. [PMID: 21870640 DOI: 10.3923/pjbs.2011.170.181] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Thyroid stimulating hormone receptor (TSHR) is a vital thyrocyte membrane protein in the thyroid gland. Thyroid Stimulating Hormone (TSH) which is a pituitary hormone is the main stimulator of thyroid gland to produce thyroid hormones, it binds with high affinity to the TSHR through weak bonds including hydrophobic, ionic, hydrogen bonds and trigger the initial steps in thyroid gland stimulation to produce the related hormones. This study was carried out at department of biochemistry of Golestan university of medical sciences. All the related articles related to TSHR modification happened due to mutations and any other alterations which affect the level of TSH-TSHR complex were studied and the main points were extracted out of the pile of information and were organized as present review. TSH-TSHR is the initial and vital step of a long process of thyroid hormone production within the thyroid gland. Any alteration on the TSH-TSHR affinity which may happen due to the direct effect of TSHR modification eventually lead to the serious adverse effects of either hypothyroidism or hyperthyroidism if the TSH-TSHR level are suppressed or elevated, respectively. The prime cause of the thyroid disorders relay on the possible modification on the biochemical structure of TSHR with subsequent alteration on the level of TSH-TSHR complex. TSHR mutation accompanied by biochemical modification, unable it to bind properly to TSH. In some other conditions such mutation leave a TSHR with either of higher affinity towards to TSH or even TSHR which can be activated in the absence of TSH. The structural modification of TSHR and alteration in the level of TSH-TSHR in the thyroid gland eventually lead to thyroid disorders either of hypothyroidism or hyperthyroidism.
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Affiliation(s)
- Azad Reza Mansourian
- Biochemistry and Metabolic Disorder Research Center, Gorgan Medial School, Golestan University of Medical Sciences, Gorgan, Iran
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