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Borges MDF, Domené HM, Scaglia PA, Lara BHJ, Palhares HMDC, Santos AVA, Gonçalves ALF, Oliveira MM, Marqui ABTD. A RECURRENT MUTATION IN TSHB GENE UNDERLYING CENTRAL CONGENITAL HYPOTHYROIDISM UNDETECTABLE IN NEONATAL SCREENING. REVISTA PAULISTA DE PEDIATRIA 2019; 37:520-524. [PMID: 31166470 PMCID: PMC6821475 DOI: 10.1590/1984-0462/;2019;37;4;00017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 06/10/2018] [Indexed: 11/22/2022]
Abstract
Objective: To describe the case of a patient with central congenital hypothyroidism
(CCH) due to a recurrent mutation in the TSHB gene, as well as to conduct a
genetic study of his family. Case description: It is presented a case report of a 5-month-old boy with a delayed diagnosis
of isolated CCH in whom the molecular analysis was performed 12 years later
and detected a recurrent mutation (c.373delT) in TSHB gene. The parents and
sister were carriers of the mutant allele. Comments: The c.373delT mutation has previously been reported in patients from Brazil,
Germany, Belgium, United States, Switzerland, Argentina, France, Portugal,
United Kingdom and Ireland. In summary, our case and other ones reported in
the literature support the theory that this mutation may be a common cause
of isolated TSH deficiency. Isolated TSH deficiency is not detected by
routine TSH-based neonatal screening, representing a clinical challenge.
Therefore, when possible, molecular genetic study is indicated.
Identification of affected and carriers allows the diagnosis, treatment and
adequate genetic counseling.
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The Pathogenic TSH β-subunit Variant C105Vfs114X Causes a Modified Signaling Profile at TSHR. Int J Mol Sci 2019; 20:ijms20225564. [PMID: 31703413 PMCID: PMC6888357 DOI: 10.3390/ijms20225564] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/1970] [Revised: 11/01/2019] [Accepted: 11/03/2019] [Indexed: 01/05/2023] Open
Abstract
1) Background: Central congenital hypothyroidism (CCH) is a rare endocrine disorder that can be caused by mutations in the β-subunit of thyrotropin (TSHB). The TSHB mutation C105Vfs114X leads to isolated thyroid-stimulating-hormone-(TSH)-deficiency and results in a severe phenotype. The aim of this study was to gain more insight into the underlying molecular mechanism and the functional effects of this mutation based on two assumptions: a) the three-dimensional (3D) structure of TSH should be modified with the C105V substitution, and/or b) whether the C-terminal modifications lead to signaling differences. 2) Methods: wild-type (WT) and different mutants of hTSH were generated in human embryonic kidney 293 cells (HEK293 cells) and TSH preparations were used to stimulate thyrotropin receptor (TSHR) stably transfected into follicular thyroid cancer cells (FTC133-TSHR cells) and transiently transfected into HEK293 cells. Functional characterization was performed by determination of Gs, mitogen activated protein kinase (MAPK) and Gq/11 activation. 3) Results: The patient mutation C105Vfs114X and further designed TSH mutants diminished cyclic adenosine monophosphate (cAMP) signaling activity. Surprisingly, MAPK signaling for all mutants was comparable to WT, while none of the mutants induced PLC activation. 4) Conclusion: We characterized the patient mutation C105Vfs114X concerning different signaling pathways. We identified a strong decrease of cAMP signaling induction and speculate that this could, in combination with diverse signaling regarding the other pathways, accounting for the patient's severe phenotype.
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Ebrhim RS, Bruellman RJ, Watanabe Y, Creech MK, Abdullah MA, Dumitrescu AM, Refetoff S, Weiss RE. Central Congenital Hypothyroidism Caused by a Novel Mutation, C47W, in the Cysteine Knot Region of TSHβ. Horm Res Paediatr 2019; 92:390-394. [PMID: 31914441 PMCID: PMC7308213 DOI: 10.1159/000504981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 11/25/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Isolated central congenital hypothyroidism (ICCH) is a rare form (1:50,000 newborns) of congenital hypothyroidism, which can present with growth and neuropsychological retardation. Unlike the more common primary CH (1:1,500-1:4,000), which presents on newborn screening with elevated serum thyroid-stimulating hormone (TSH) and low thyroxine (T4) and triiodothyronine (T3), ICCH presents with low TSH and low thyroid hormone levels. ICCH, therefore, may be missed in most newborn screens that are based only on elevated TSH. Most cases of ICCH have been associated with mutations in the TSHβ gene. PATIENT We present a consanguineous Sudanese family where the proband was diagnosed with "atypical" CH (serum TSH was low, not high). INTERVENTION AND OUTCOME The propositus underwent whole-exome sequencing, and the C47W TSHβ mutation was identified. Sanger sequencing confirmed the proband to be homozygous for C47W, and both parents were heterozygous for the same mutation. The mutation was predicted by several in silico methods to have a deleterious effect (SIFT 0.0, Damaging; Polyphen2_HDIV 0.973, probably damaging; MutationTaster 1, disease causing; and CADD 3.17, 16.62). C47W affects the first cysteine of the cysteine knot of the TSHβ subunit. The cysteine knot region of TSHβ is highly conserved across species and is critical for binding to the TSH receptor. Only two other mutations were previously reported along the cysteine knot and showed consistently low or undetectable serum TSH and low T4 and T3 levels. Other TSHβ gene mutations causing ICCH have been reported in the "seatbelt" region, necessary for TSHβ dimerization with the alpha subunit. CONCLUSIONS Identification of a mutation in the TSHβ gene reinforces the importance of identifying ICCH that can occur in the absence of elevated serum TSH and demonstrates the functional significance of the TSHβ cysteine knot.
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Affiliation(s)
- Reham S. Ebrhim
- Department of Pediatrics and Child Health, Faculty of Medicine, University of Almughtaribeen, Khartoum, Sudan
| | - Ryan J. Bruellman
- Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida
| | - Yui Watanabe
- Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida
| | - Matthew K. Creech
- Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida
| | - Mohamed A. Abdullah
- Department of Pediatrics and Child Health, Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | | | - Samuel Refetoff
- Department of Medicine, The University of Chicago, Chicago, Illinois.,Department of Pediatrics The University of Chicago, Chicago, Illinois.,Department of Committee on Genetics The University of Chicago, Chicago, Illinois
| | - Roy E. Weiss
- Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida
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Nicholas A, Jaleel S, Lyons G, Schoenmakers E, Dattani M, Crowne E, Bernhard B, Kirk J, Roche E, Chatterjee V, Schoenmakers N. Molecular spectrum of TSHβ subunit gene defects in central hypothyroidism in the UK and Ireland. Clin Endocrinol (Oxf) 2017; 86:410-418. [PMID: 27362444 PMCID: PMC5324561 DOI: 10.1111/cen.13149] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 06/24/2016] [Accepted: 06/28/2016] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Homozygous mutations in the TSH beta subunit gene (TSHB) result in severe, isolated, central congenital hypothyroidism (CCH). This entity evades diagnosis in TSH-based congenital hypothyroidism (CH) screening programmes in the UK and Ireland. Accordingly, genetic diagnosis, enabling ascertainment of affected relatives in families, is critical for prompt diagnosis and treatment of the disorder. DESIGN, PATIENTS AND MEASUREMENTS Four cases of isolated TSH deficiency from three unrelated families in the UK and Ireland were investigated for mutations or deletions in TSHB. Haplotype analysis, to investigate a founder effect, was undertaken in cases with identical mutations (c.373delT). RESULTS Two siblings in kindred 1 were homozygous for a previously described TSHB mutation (c.373delT). In kindreds 2 and 3, the affected individuals were compound heterozygous for TSHB c.373delT and either a 5·4-kB TSHB deletion (kindred 2, c.1-4389_417*195delinsCTCA) or a novel TSHB missense mutation (kindred 3, c.2T>C, p.Met1?). Neurodevelopmental retardation, following delayed diagnosis and treatment, was present in 3 cases. In contrast, the younger sibling in kindred 1 developed normally following genetic diagnosis and treatment from birth. CONCLUSIONS This study, including the identification of a second, novel, TSHB deletion, expands the molecular spectrum of TSHB defects and suggests that allele loss may be a commoner basis for TSH deficiency than previously suspected. Delayed diagnosis and treatment of profound central hypothyroidism in such cases result in neurodevelopmental retardation. Inclusion of thyroxine (T4) plus thyroxine-binding globulin (TBG), or free thyroxine (FT4) in CH screening, together with genetic case ascertainment enabling earlier therapeutic intervention, could prevent such adverse sequelae.
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Affiliation(s)
- A.K. Nicholas
- University of Cambridge Metabolic Research LaboratoriesWellcome Trust‐Medical Research Council Institute of Metabolic ScienceAddenbrooke's HospitalCambridgeUK
| | - S. Jaleel
- Department of Paediatric Endocrinology & DiabetesNational Children's HospitalAMNCHDublinIreland
| | - G. Lyons
- University of Cambridge Metabolic Research LaboratoriesWellcome Trust‐Medical Research Council Institute of Metabolic ScienceAddenbrooke's HospitalCambridgeUK
| | - E. Schoenmakers
- University of Cambridge Metabolic Research LaboratoriesWellcome Trust‐Medical Research Council Institute of Metabolic ScienceAddenbrooke's HospitalCambridgeUK
| | - M.T. Dattani
- University College London Institute of Child HealthDevelopmental Endocrinology Research GroupSection of Genetics and Epigenetics in Health and DiseaseGenetics and Genomic Medicine ProgrammeLondonUK
| | - E. Crowne
- Department of Paediatric Endocrinology & DiabetesBristol Royal Hospital for ChildrenUniversity Hospitals Bristol NHS Foundation TrustBristolUK
| | - B. Bernhard
- Department of Clinical GeneticsNorth West Thames Regional Genetics ServiceNorth West London Hospitals NHS TrustHarrowUK
| | - J. Kirk
- Department of EndocrinologyBirmingham Children's HospitalBirminghamUK
| | - E.F. Roche
- Department of Paediatric Endocrinology & DiabetesNational Children's HospitalAMNCHDublinIreland
- University of DublinTrinity College DublinDublinIreland
| | - V.K. Chatterjee
- University of Cambridge Metabolic Research LaboratoriesWellcome Trust‐Medical Research Council Institute of Metabolic ScienceAddenbrooke's HospitalCambridgeUK
| | - N. Schoenmakers
- University of Cambridge Metabolic Research LaboratoriesWellcome Trust‐Medical Research Council Institute of Metabolic ScienceAddenbrooke's HospitalCambridgeUK
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Kleinau G, Kalveram L, Köhrle J, Szkudlinski M, Schomburg L, Biebermann H, Grüters-Kieslich A. Minireview: Insights Into the Structural and Molecular Consequences of the TSH-β Mutation C105Vfs114X. Mol Endocrinol 2016; 30:954-64. [PMID: 27387040 DOI: 10.1210/me.2016-1065] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Naturally occurring thyrotropin (TSH) mutations are rare, which is also the case for the homologous heterodimeric glycoprotein hormones (GPHs) follitropin (FSH), lutropin (LH), and choriogonadotropin (CG). Patients with TSH-inactivating mutations present with central congenital hypothyroidism. Here, we summarize insights into the most frequent loss-of-function β-subunit of TSH mutation C105Vfs114X, which is associated with isolated TSH deficiency. This review will address the following question. What is currently known on the molecular background of this TSH variant on a protein level? It has not yet been clarified how C105Vfs114X causes early symptoms in affected patients, which are comparably severe to those observed in newborns lacking any functional thyroid tissue (athyreosis). To better understand the mechanisms of this mutant, we have summarized published reports and complemented this information with a structural perspective on GPHs. By including the ancestral TSH receptor agonist thyrostimulin and pathogenic mutations reported for FSH, LH, and choriogonadotropin in the analysis, insightful structure function and evolutionary restrictions become apparent. However, comparisons of immunogenicity and bioactivity of different GPH variants is hindered by a lack of consensus for functional analysis and the diversity of used GPH assays. Accordingly, relevant gaps of knowledge concerning details of GPH mutation-related effects are identified and highlighted in this review. These issues are of general importance as several previous and recent studies point towards the high impact of GPH variants in differential signaling regulation at GPH receptors (GPHRs), both endogenously and under diseased conditions. Further improvement in this area is of decisive importance for the development of novel targeted therapies.
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Affiliation(s)
- Gunnar Kleinau
- Institute of Experimental Pediatric Endocrinology (G.K., L.K., H.B.), Charité-Universitätsmedizin, Berlin, 13353 Germany; Institute of Experimental Endocrinology (J.K., L.S.), Charité-Universitätsmedizin Berlin, 13353 Germany; Trophogen, Inc (M.S.), Rockville, Maryland 20850; and Department of Pediatric Endocrinology and Diabetes (A.G.-K.), Charité-Universitätsmedizin, Berlin, 13353 Germany
| | - Laura Kalveram
- Institute of Experimental Pediatric Endocrinology (G.K., L.K., H.B.), Charité-Universitätsmedizin, Berlin, 13353 Germany; Institute of Experimental Endocrinology (J.K., L.S.), Charité-Universitätsmedizin Berlin, 13353 Germany; Trophogen, Inc (M.S.), Rockville, Maryland 20850; and Department of Pediatric Endocrinology and Diabetes (A.G.-K.), Charité-Universitätsmedizin, Berlin, 13353 Germany
| | - Josef Köhrle
- Institute of Experimental Pediatric Endocrinology (G.K., L.K., H.B.), Charité-Universitätsmedizin, Berlin, 13353 Germany; Institute of Experimental Endocrinology (J.K., L.S.), Charité-Universitätsmedizin Berlin, 13353 Germany; Trophogen, Inc (M.S.), Rockville, Maryland 20850; and Department of Pediatric Endocrinology and Diabetes (A.G.-K.), Charité-Universitätsmedizin, Berlin, 13353 Germany
| | - Mariusz Szkudlinski
- Institute of Experimental Pediatric Endocrinology (G.K., L.K., H.B.), Charité-Universitätsmedizin, Berlin, 13353 Germany; Institute of Experimental Endocrinology (J.K., L.S.), Charité-Universitätsmedizin Berlin, 13353 Germany; Trophogen, Inc (M.S.), Rockville, Maryland 20850; and Department of Pediatric Endocrinology and Diabetes (A.G.-K.), Charité-Universitätsmedizin, Berlin, 13353 Germany
| | - Lutz Schomburg
- Institute of Experimental Pediatric Endocrinology (G.K., L.K., H.B.), Charité-Universitätsmedizin, Berlin, 13353 Germany; Institute of Experimental Endocrinology (J.K., L.S.), Charité-Universitätsmedizin Berlin, 13353 Germany; Trophogen, Inc (M.S.), Rockville, Maryland 20850; and Department of Pediatric Endocrinology and Diabetes (A.G.-K.), Charité-Universitätsmedizin, Berlin, 13353 Germany
| | - Heike Biebermann
- Institute of Experimental Pediatric Endocrinology (G.K., L.K., H.B.), Charité-Universitätsmedizin, Berlin, 13353 Germany; Institute of Experimental Endocrinology (J.K., L.S.), Charité-Universitätsmedizin Berlin, 13353 Germany; Trophogen, Inc (M.S.), Rockville, Maryland 20850; and Department of Pediatric Endocrinology and Diabetes (A.G.-K.), Charité-Universitätsmedizin, Berlin, 13353 Germany
| | - Annette Grüters-Kieslich
- Institute of Experimental Pediatric Endocrinology (G.K., L.K., H.B.), Charité-Universitätsmedizin, Berlin, 13353 Germany; Institute of Experimental Endocrinology (J.K., L.S.), Charité-Universitätsmedizin Berlin, 13353 Germany; Trophogen, Inc (M.S.), Rockville, Maryland 20850; and Department of Pediatric Endocrinology and Diabetes (A.G.-K.), Charité-Universitätsmedizin, Berlin, 13353 Germany
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Pappa T, Johannesen J, Scherberg N, Torrent M, Dumitrescu A, Refetoff S. A TSHβ Variant with Impaired Immunoreactivity but Intact Biological Activity and Its Clinical Implications. Thyroid 2015; 25:869-76. [PMID: 25950606 PMCID: PMC4533086 DOI: 10.1089/thy.2015.0096] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Thyrotropin (TSH) deficiency caused by TSHβ gene mutations is a rare form of congenital central hypothyroidism. Nine different TSHβ gene mutations have been reported, all with clinical manifestations. The aim was to identify the genetic cause of undetectable TSH levels in two siblings with clinical euthyroidism. METHODS Two brothers born to consanguineous Pakistani parents presented with undetectable serum TSH but normal iodothyronine concentrations and no clinical signs of hypothyroidism. Direct sequencing of the TSHβ gene, functional and immunological studies, protein homology modeling, and population frequency analysis were performed to characterize the cause of undetectable TSH in this family. RESULTS Direct sequencing of the TSHβ gene revealed that the two brothers were homozygous for a single nucleotide substitution (c.223A>G) resulting in the replacement of arginine 55 with glycine (R55G). This variant was found in 12 out of 5008 alleles in the 1000 Genomes project (all South Asian). Serum TSH of the two brothers was undetectable in two of five platforms, both produced by Siemens, whereas TSH levels of the heterozygous brother and mother were half compared to the other three platforms (Roche Elecsys, Abbott Architect, and Beckman Coulter DxI). The falsely low TSH concentration was caused by the monoclonal antibody not recognizing the region containing the variant amino acid. This is supported by the fact that arginine modification--following phenylglyoxal treatment--led to a significant (96%) decrease in the TSH measurement with the Siemens platforms. Predictions based on PolyPhen-2 and in silico modeling revealed no functional impairment of the variant TSH. CONCLUSIONS A TSHβ variant with impaired immunoreactivity, but not bioactivity, is reported, and its biochemical impact in the homo- and heterozygous state is demonstrated. It is also shown that failure to bind to the monoclonal antibody is a direct consequence of the amino acid substitution.
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Affiliation(s)
- Theodora Pappa
- Department of Medicine, The University of Chicago, Chicago, Illinois
| | - Jesper Johannesen
- Paediatric Department at Copenhagen University Hospital, Herlev, Denmark
| | - Neal Scherberg
- Department of Medicine, The University of Chicago, Chicago, Illinois
| | - Maricel Torrent
- Department of Molecular Modeling, Discovery, Research and Development, AbbVie, North Chicago, Illinois
| | | | - Samuel Refetoff
- Department of Medicine, The University of Chicago, Chicago, Illinois
- Department of Pediatrics and the Committee on Genetics, The University of Chicago, Chicago, Illinois
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Hermanns P, Couch R, Leonard N, Klotz C, Pohlenz J. A novel deletion in the thyrotropin Beta-subunit gene identified by array comparative genomic hybridization analysis causes central congenital hypothyroidism in a boy originating from Turkey. Horm Res Paediatr 2015; 82:201-5. [PMID: 25012771 DOI: 10.1159/000362413] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 03/24/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Isolated central congenital hypothyroidism (ICCH) is rare but important. Most ICCH patients are diagnosed later, which results in severe growth failure and intellectual disability. OBJECTIVE We describe a boy with ICCH due to a large homozygous TSHβ gene deletion. RESULTS A 51-day-old male Turkish infant, whose parents were first cousins, was admitted for evaluation of prolonged jaundice. His clinical appearance was compatible with hypothyroidism. Venous thyrotropin (TSH) was undetectably low, with a subsequent low free T4 and a low free T3, suggestive of central hypothyroidism. Using different PCR protocols, we could not amplify both coding exons of the boy's TSHβ gene, which suggested a deletion. An array comparative genomic hybridization (aCGH) using specific probes around the TSHβ gene locus showed him to be homozygous for a 6-kb deletion spanning all exons and parts of the 5' untranslated region of the gene. CONCLUSIONS Infants who are clinically suspected of having hypothyroidism should be evaluated thoroughly, even if their TSH-based screening result is normal. In cases with ICCH and undetectably low TSH serum concentrations, a TSHβ gene deletion should be considered; aCGH should be performed when gene deletions are suspected. In such cases, PCR-based sequencing techniques give negative results.
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Affiliation(s)
- Pia Hermanns
- Department of Pediatrics, Johannes Gutenberg University Medical School, Mainz, Germany
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Epistasis between polymorphisms in TSHB and ADAMTS16 is associated with premature ovarian failure. Menopause 2014; 21:890-5. [DOI: 10.1097/gme.0000000000000172] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Koklu E, Gunes T, Ozturk MA, Akcakus M, Buyukkayhan D, Kurtoglu S. Cutis laxa associated with central hypothyroidism owing to isolated thyrotropin deficiency in a newborn. Pediatr Dermatol 2007; 24:525-8. [PMID: 17958802 DOI: 10.1111/j.1525-1470.2007.00509.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cutis laxa is an uncommon entity characterized by laxity of the skin, which hangs in loose folds, producing an appearance of premature aging. It can be subdivided into congenital and acquired forms. Genetic forms of cutis laxa include at least three forms of recessive disease, an X-linked form also termed occipital horn syndrome and an autosomal dominant form. Isolated pituitary hormone deficiency can be induced by many causes including mechanical destruction of the hypothalamo-pituitary axis, neoplasm, inflammation, and injury and genetic defects of pituitary hormone production and secretion. Isolated-thyrotropin deficiency has been considered to be a rare disease. We report a newborn with autosomal recessive form of congenital cutis laxa, who had congenital hypothyroidism owing to isolated thyrotropin deficiency. To the best of our knowledge, this is the first instance of this association to be reported in the literature.
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Affiliation(s)
- Esad Koklu
- Division of Neonatology, Erciyes University, Kayseri, Turkey.
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