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El-Ella SSA, Khattab ESAEH, Beddah RK, Barseem NF. Genetic Variability of the Paired Box Transcription Factor; PAX8 Gene: Guidance Towards Treatment Strategies in a Cohort of Congenital Hypothyroidism. Horm Metab Res 2021; 53:311-318. [PMID: 33862642 DOI: 10.1055/a-1409-5310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The contribution of PAX8 genetic variants to congenital hypothyroidism (CH) is not well understood. We aimed to study the genetic variability of exons 3 and 5 of PAX8 gene among a cohort of children with congenital hypothyroidism in correspondence to their clinical aspect. Blood samples were collected from 117 children (63 girls and 54 boys) with CH and enrolled as cases (Group I). All cases underwent biochemical confirmation with low FT4 and high TSH levels and thyroid gland imaging, along with equal number of matched apparently healthy individuals who served as controls (Group II). Genomic materials for exons 3 and 5 of PAX8 gene were extracted, amplified by PCR, detected by electrophoresis, purified, and sequenced by the Sanger technique through the application of ABI 3730x1 DNA Sequencer. Out of 117 cases, eight different effective PAX8 mutations were detected in exon 3 (G23D, V35I, I34T, Q40P, p.R31C, p.R31H, p.R31A, and p.I47T) in 14 patients with their sonographic findings ranged from normal, hypoplastic to thyroid agenesis. Besides the reported mutations, one novel mutation; R31A was detected in 1 euotopic case. Exon 5 analysis revealed no detected mutations elsewhere. In contrast, all healthy control children showed no mutation and normal sonographic findings. Mutations in exon 3 of PAX8 gene, implies its important role in thyroid development and function, as a first estimate of PA8 mutation rate in Egyptian patients with CH having normal and dysgenetic gland. Using ultrasound is mandatory for diagnosis and guiding the treatment of children with CH.
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Affiliation(s)
- Sohier S Abou El-Ella
- Genetic and Endocrinology Unit, Pediatric Department, Menoufia University, Shebin ElKoum, Menofia, Egypt
| | | | - Rehab K Beddah
- Genetic and Endocrinology Unit, Pediatric Department, Menoufia University, Shebin ElKoum, Menofia, Egypt
| | - Naglaa Fathy Barseem
- Genetic and Endocrinology Unit, Pediatric Department, Menoufia University, Shebin ElKoum, Menofia, Egypt
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Camats N, Baz-Redón N, Fernández-Cancio M, Clemente M, Campos-Martorell A, Jaimes N, Antolín M, Garcia-Arumí E, Blasco-Pérez L, Paramonov I, Mogas E, Soler-Colomer L, Yeste D. Phenotypic Variability of Patients With PAX8 Variants Presenting With Congenital Hypothyroidism and Eutopic Thyroid. J Clin Endocrinol Metab 2021; 106:e152-e170. [PMID: 33029631 DOI: 10.1210/clinem/dgaa711] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/05/2020] [Indexed: 11/19/2022]
Abstract
PURPOSE Thyroid dyshormonogenesis is a heterogeneous group of hereditary diseases produced by a total/partial blockage of the biochemical processes of thyroid-hormone synthesis and secretion. Paired box 8 (PAX8) is essential for thyroid morphogenesis and thyroid hormone synthesis. We aimed to identify PAX8 variants in patients with thyroid dyshormonogenesis and to analyze them with in vitro functional studies. PATIENTS AND METHODS Nine pediatric patients with a eutopic thyroid gland were analyzed by the Catalan screening program for congenital hypothyroidism. Scintigraphies showed absent, low, or normal uptake. Only one patient had a hypoplastic gland. On reevaluation, perchlorate discharge test was negative or compatible with partial iodine-organization deficit. After evaluation, 8 patients showed permanent mild or severe hypothyroidism. Massive-sequencing techniques were used to detect variants in congenital hypothyroidism-related genes. In vitro functional studies were based on transactivating activity of mutant PAX8 on a TG-gene promoter and analyzed by a dual-luciferase assays. RESULTS We identified 7 heterozygous PAX8 exonic variants and 1 homozygous PAX8 splicing variant in 9 patients with variable phenotypes of thyroid dyshormonogenesis. Five were novel and 5 variants showed a statistically significant impaired transcriptional activity of TG promoter: 51% to 78% vs the wild type. CONCLUSIONS Nine patients presented with PAX8 candidate variants. All presented with a eutopic thyroid gland and 7 had deleterious variants. The phenotype of affected patients varies considerably, even within the same family; but, all except the homozygous patient presented with a normal eutopic thyroid gland and thyroid dyshormonogenesis. PAX8 functional studies have shown that 6 PAX8 variants are deleterious. Our studies have proven effective in evaluating these variants.
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Affiliation(s)
- Núria Camats
- Growth and Development group, Vall d'Hebron Research Institute (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
- CIBERER, ISCIII, Madrid, Spain
| | - Noelia Baz-Redón
- Growth and Development group, Vall d'Hebron Research Institute (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Pediatrics, Obstetrics and Gynecology and Preventive Medicine Department, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Mónica Fernández-Cancio
- Growth and Development group, Vall d'Hebron Research Institute (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
- CIBERER, ISCIII, Madrid, Spain
| | - María Clemente
- Growth and Development group, Vall d'Hebron Research Institute (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
- CIBERER, ISCIII, Madrid, Spain
- Pediatrics, Obstetrics and Gynecology and Preventive Medicine Department, Universitat Autònoma de Barcelona, Bellaterra, Spain
- Pediatric Endocrinology Section, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Ariadna Campos-Martorell
- Growth and Development group, Vall d'Hebron Research Institute (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Pediatrics, Obstetrics and Gynecology and Preventive Medicine Department, Universitat Autònoma de Barcelona, Bellaterra, Spain
- Pediatric Endocrinology Section, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Nadya Jaimes
- Department of Pediatric Endocrinology, Hospital Fundación la Misericordia HOMI, Bogotá, Colombia
| | - María Antolín
- Department of Clinical and Molecular Genetics and Rare Disease, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Medicine Genetics Group, VHIR, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Elena Garcia-Arumí
- Department of Clinical and Molecular Genetics and Rare Disease, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Medicine Genetics Group, VHIR, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Research Group on Neuromuscular and Mitochondrial Disorders, VHIR, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Laura Blasco-Pérez
- Department of Clinical and Molecular Genetics and Rare Disease, Hospital Universitari Vall d'Hebron, Barcelona, Spain
- Medicine Genetics Group, VHIR, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Ida Paramonov
- Department of Clinical and Molecular Genetics and Rare Disease, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Eduard Mogas
- Pediatric Endocrinology Section, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Laura Soler-Colomer
- Pediatric Endocrinology Section, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Diego Yeste
- Growth and Development group, Vall d'Hebron Research Institute (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
- CIBERER, ISCIII, Madrid, Spain
- Pediatrics, Obstetrics and Gynecology and Preventive Medicine Department, Universitat Autònoma de Barcelona, Bellaterra, Spain
- Pediatric Endocrinology Section, Hospital Universitari Vall d'Hebron, Barcelona, Spain
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Novel non-synonymous mutations of PAX8 in a cohort of Chinese with congenital hypothyroidism. Chin Med J (Engl) 2019; 132:1322-1327. [PMID: 30888984 PMCID: PMC6629355 DOI: 10.1097/cm9.0000000000000213] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The transcription factor paired box 8 (PAX8) was associated with type 2 congenital non-goitrous hypothyroidism (CHNG2), a clinical phenotype of congenital hypothyroidism (CH). Though studied in a few regions with different ethnicities, the incidence of PAX8 mutations varied, even among Chinese cohorts in different regions. This study aimed to identify and characterize PAX8 mutations and explore the prevalence of its mutations in another cohort of CH. METHODS The 105 unrelated Chinese patients with CH were collected from four major hospitals. Exomes of the 105 samples were sequenced by Hiseq 2000 platform to identify mutations of PAX8 on genomic DNAs extracted from peripheral blood samples. Luciferase reporter assays were used to assess the effects of mutations on the transcription of thyroid peroxidase (TPO). RESULTS Three PAX8 mutations in four subjects were identified in 105 samples. One variant, rs189229644, was detected in two subjects, and categorized as uncertain significance. The other two missense mutations (275T>C/Ile92Thr and 398G>A/Arg133Gln) were not detected in three large-scale genotyping projects, namely 1000 Genome Project, Exome Aggregation Consortium and GO Exome Sequencing Project. Functional studies for the two mutations revealed that they could impair the transcription ability of PAX8 on one of its target genes, TPO. Therefore, the two mutations were causative for the pathogenesis of CHNG2. After combining the studies of PAX8 mutations, an average frequency of 1.74% (21/1209) could be obtained in Chinese patients with CH. CONCLUSION The study specifically demonstrates the role of two mutations in impairing the transcription ability of PAX8, which should be considered as pathogenic variants for CH.
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Liu S, Wang X, Zou H, Ge Y, Wang F, Wang Y, Yan S, Xia H, Xing M. Identification and characterization of novel PAX8 mutations in Congenital Hypothyroidism(CH) in a Chinese population. Oncotarget 2018; 8:8707-8716. [PMID: 28060725 PMCID: PMC5352434 DOI: 10.18632/oncotarget.14419] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 11/30/2016] [Indexed: 11/25/2022] Open
Abstract
Objective Based on mutations in PAX8 is associated with thyroid dysgenesis. We aim to identify and characterize PAX8 mutations in a large cohort of congenital hypothyroidism(CH) from thyroid dysgenesis in Chinese population. Methods We screened 453 unrelated Chinese patients with CH from thyroid dysgenesis for PAX8 mutations by sequencing the whole coding regions of PAX8 on genomic DNA isolated from blood. Cell transfection assays using various vector constructs and induced mutagenesis as well as electrophoretic mobility shift assays were used to investigate the effects of selected mutations on the transcribing and binding activities of PAX8 at the promoters of target genes for thyroglobulin (TG) and thyroperoxidase (TPO). Results Five PAX8 mutations were found, yielding a mutation prevalence of 5/453 (1.1%). We selected two mutations in the critical paired domain of PAX8 and generated mutants D94N and G41V. We demonstrated G41V was unable to bind the specific sequence in the promoters of TG and TPO and activate them. D94N could bind to TG and TPO promoters and normally activate the TG promoter transcription but not the TPO promoter transcription. We also demonstrated a dominant negative role of the PAX8 mutants in impairing the function of the wild-type PAX8. Conclusion We for the first time documented the prevalence and characterized the function of PAX8 mutations in CH in Chinese population. The study specifically demonstrated the role of novel mutations D94N and G41V in impairing the function of PAX8, providing further evidence for genetic PAX8 defects as a disease mechanism in CH.
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Affiliation(s)
- Shiguo Liu
- Prenatal Diagnosis Center, The Affiliated Hospital of Qingdao University, Qingdao, China.,Genetic Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Xueqin Wang
- Department of Biochemistry and Molecular Biology, School of Medicine, Qingdao University, Qingdao, China.,National Research Institute for Family Planning, Beijing, China
| | - Hui Zou
- Neonatal Screening Center, Jinan Women & Children Medical Healthcare Center, Jinan, China
| | - Yinlin Ge
- Department of Biochemistry and Molecular Biology, School of Medicine, Qingdao University, Qingdao, China
| | - Fang Wang
- Department of Endocrinology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Yangang Wang
- Department of Endocrinology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Shengli Yan
- Department of Endocrinology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Hongfei Xia
- National Research Institute for Family Planning, Beijing, China.,Graduate School, Peking Union Medical College, Beijing, China.,World Health Organization Collaborating Centre for Research in Human Reproduction, Beijing, China
| | - Mingzhao Xing
- Department of Endocrinology, The Affiliated Hospital of Qingdao University, Qingdao, China.,Division of Endocrinology, Diabetes & Metabolism, Department of Medicine, The Johns Hopkins University School of Medicine, USA
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Wang F, Liu C, Jia X, Liu X, Xu Y, Yan S, Jia X, Huang Z, Liu S, Gu M. Next-generation sequencing of NKX2.1, FOXE1, PAX8, NKX2.5, and TSHR in 100 Chinese patients with congenital hypothyroidism and athyreosis. Clin Chim Acta 2017; 470:36-41. [PMID: 28455095 DOI: 10.1016/j.cca.2017.04.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 04/21/2017] [Accepted: 04/22/2017] [Indexed: 11/20/2022]
Abstract
BACKGROUND The abnormal expression of certain transcription factors (NKX2.1, FOXE1, NKX2.5, and PAX8) and thyroid stimulating hormone receptor (TSHR) genes has been associated with athyreosis, which is a form of thyroid dysgenesis (TD). We aimed to identify candidate gene mutations in CH patients with athyreosis and to establish the genotype-phenotype correlations in a Chinese population. METHODS The exons and flanking sequences of NKX2.1, FOXE1, NKX2.5, PAX8, and TSHR were screened by next-generation sequencing and further confirmed by direct Sanger sequencing. The mutation frequencies were calculated and compared against databases. The relationship between genotype and phenotype was also determined. RESULTS Seven variants were detected in TSHR-p.P52T, p.G132R, p.M164K, p.R450H, p.C700E, p.A522V, and p.R528S. The p. G132R, p. M164K and p. R528S variants were first identified in public databases. Five variants (p.G44D, p.G360V, p.R401Q, p.L418I, and p.E453Q) were found in NKX2.1 and one variant (p.P243T) was detected in FOXE1. In addition, one variant (p.N291I) was found in NKX2.5 and two variants (p.A355V and c.-26G>A) were detected in PAX8. CONCLUSIONS Our study indicated that TSHR mutations have phenotypic variability and has further expanded the mutation spectrum of TSHR. We also revealed that the rate of NKX2.1, FOXE1, NKX2.5, and PAX8 mutations were low in patients with CH and athyreosis, in contrast to the higher rate of TSHR mutations.
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Affiliation(s)
- Fang Wang
- Prenatal Diagnosis Center, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, China; Department of Endocrinology and Metabolism, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, China
| | - Chang Liu
- Department of Endocrinology and Metabolism, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, China
| | - Xiuhua Jia
- Clinic Lab, Linyi Maternal and Children Health's Hospital, Linyi, China
| | - Xiangju Liu
- Genetics Diagnostic Lab, Tai'an Maternity and Child Care Hospital, Tai'an 271000, China
| | - Yinglei Xu
- Prenatal Diagnosis Center, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, China
| | - Shengli Yan
- Department of Endocrinology and Metabolism, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, China
| | - Xuewen Jia
- Department of Cardiovascular, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, China
| | - Zuzhou Huang
- Clinical Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, China
| | - Shiguo Liu
- Prenatal Diagnosis Center, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, China.
| | - Maosheng Gu
- Genetic Medicine Center, Xuzhou Maternal and Children Health's Hospital, Xuzhou 221009, China.
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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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