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1.
Medicine (Baltimore) ; 98(39): e17342, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31574874

RESUMO

RATIONALE: The karyotype 49,XXXXY is a rare form of Klinefelter syndrome usually presenting with ambiguous genitalia, facial dysmorphism, mental retardation, and a combination of cardiac, skeletal, and other malformations. PATIENT CONCERNS: We describe a 19-year-old man, whose chromosomal analysis of peripheral blood revealed a karyotype of 49,XXXXY. His mental development and motor ability were significantly delayed. At the age of 19, he had failed to develop secondary sexual characteristics. His random blood glucose level was 19.61 mmol/L, and he showed dry mouth, polydipsia, and polyuria. He had a characteristic facial appearance with prognathism, widened nasal bridge, and strabismus. His bilateral elbow rotation was limited. He had atrophic testes with micropenis. Ophthalmic examination revealed a polar cataract in both eyes. DIAGNOSIS: He was diagnosed with Klinefelter syndrome associated with cleft palate, hypothyroidism, cataracts, diabetes, and other anomalies. INTERVENTIONS: After the initial diagnosis, the patient received intensive insulin therapy to correct hyperglycemia, and he received calcium and vitamin D supplements. The patient also received testosterone and thyroid hormone replacement therapy for primary hypogonadism. OUTCOMES: The patient was discharged 12 days after receiving treatment; meanwhile, there were no clinical symptoms of dry mouth, polyuria and polyuria, and his blood glucose level was controlled. LESSONS: The combination of cleft palate, hypothyroidism, cataracts, diabetes, and osteoporosis in 49,XXXXY syndrome has not yet been reported. Early treatment and appropriate care can significantly improve the patient's quality of life and prevent serious consequences.


Assuntos
Catarata/congênito , Fissura Palatina/genética , Hipotireoidismo Congênito/genética , Diabetes Mellitus/congênito , Transtornos dos Cromossomos Sexuais/complicações , Anormalidades Múltiplas/genética , Aneuploidia , Cromossomos Humanos X/genética , Humanos , Cariotipagem , Masculino , Aberrações dos Cromossomos Sexuais , Transtornos dos Cromossomos Sexuais/genética , Adulto Jovem
2.
Zhongguo Dang Dai Er Ke Za Zhi ; 21(10): 972-976, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31642429

RESUMO

OBJECTIVE: To study the types and characteristics of TUBB1 mutation in children with congenital hypothyroidism (CH) and thyroid dysgenesis (TD) in Shandong, China. METHODS: Mutations of the whole coding region of the TUBB1 gene were analyzed for 289 children with CH and TD in Shandong. Whole-genome DNA was extracted from peripheral blood leukocytes. PCR multiplication was performed for the whole coding region of the TUBB1 gene. Sanger sequencing was performed for the PCR products, and a biological information analysis was performed. RESULTS: Among the 289 children with CH and TD, 4 (1.4%) were found to have a c.952C>T(p.R318W) heterozygous mutation in the TUBB1 gene, resulting in the change of tryptophan into arginine at codon 318 of TUBB1 protein. This mutation was evaluated as "potentially pathogenic" based on the classification criteria and guidelines for genetic variation by American College of Medical Genetics and Genomics. CONCLUSIONS: A novel mutation is detected in the exon of the TUBB1 gene in children with CH and TD in Shandong, suggesting that the TUBB1 gene may be a candidate pathogenic gene for CH children with TD.


Assuntos
Hipotireoidismo Congênito , Disgenesia da Tireoide , Tubulina (Proteína)/genética , Criança , China , Hipotireoidismo Congênito/genética , Análise Mutacional de DNA , Humanos , Mutação , Disgenesia da Tireoide/genética
3.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 36(7): 727-730, 2019 Jul 10.
Artigo em Chinês | MEDLINE | ID: mdl-31302922

RESUMO

OBJECTIVE: To analyze the clinical and molecular genetics features of a family affected with Say-Barber-Biesecker-Young-Simpson syndrome (SBBYSS). METHODS: High-throughput sequencing was used to detect copy number variations (CNVs) and pathogenic variant within the whole exome of the affected child. RESULTS: No pathogenic CNV was found in the child, while exome sequencing identified a heterozygous c.3367_c.3370delAGAA (p.Arg1123Argfs*6) frameshifting variant in the exon 16 of the KAT6B gene. The same variant was not found in either parent. CONCLUSION: The c.3367_c.3370delAGAA (p.R1123Rfs*6) probably underlies the disease in the affected child. Above finding has facilitated genetic counseling and prenatal diagnosis for the family.


Assuntos
Blefarofimose/genética , Hipotireoidismo Congênito/genética , Variações do Número de Cópias de DNA , Cardiopatias Congênitas/genética , Histona Acetiltransferases/genética , Deficiência Intelectual/genética , Instabilidade Articular/genética , Criança , Facies , Feminino , Humanos , Mutação , Fenótipo , Gravidez
4.
J Hum Genet ; 64(6): 561-572, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30858506

RESUMO

Variants have been identified in the embryonic ectoderm development (EED) gene in seven patients with syndromic overgrowth similar to that observed in Weaver syndrome. Here, we present three additional patients with missense variants in the EED gene. All the missense variants reported to date (including the three presented here) have localized to one of seven WD40 domains of the EED protein, which are necessary for interaction with enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2). In addition, among the seven patients reported in the literature and the three new patients presented here, all of the reported pathogenic variants except one occurred at one of four amino acid residues in the EED protein. The recurrence of pathogenic variation at these loci suggests that these residues are functionally important (mutation hotspots). In silico modeling and calculations of the free energy changes resulting from these variants suggested that they not only destabilize the EED protein structure but also adversely affect interactions between EED, EZH2, and/or H3K27me3. These cases help demonstrate the mechanism(s) by which apparently deleterious variants in the EED gene might cause overgrowth and lend further support that amino acid residues in the WD40 domain region may be mutation hotspots.


Assuntos
Anormalidades Múltiplas/genética , Hipotireoidismo Congênito/genética , Anormalidades Craniofaciais/genética , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Deformidades Congênitas da Mão/genética , Histona-Lisina N-Metiltransferase/genética , Complexo Repressor Polycomb 2/genética , Anormalidades Múltiplas/etiologia , Anormalidades Múltiplas/fisiopatologia , Adolescente , Criança , Simulação por Computador , Hipotireoidismo Congênito/etiologia , Hipotireoidismo Congênito/fisiopatologia , Anormalidades Craniofaciais/etiologia , Anormalidades Craniofaciais/fisiopatologia , Proteína Potenciadora do Homólogo 2 de Zeste/química , Feminino , Deformidades Congênitas da Mão/etiologia , Deformidades Congênitas da Mão/fisiopatologia , Histona-Lisina N-Metiltransferase/química , Humanos , Masculino , Simulação de Dinâmica Molecular , Taxa de Mutação , Mutação de Sentido Incorreto/genética , Complexo Repressor Polycomb 2/química , Conformação Proteica , Repetições WD40/genética , Sequenciamento Completo do Exoma
5.
Biomed Res Int ; 2019: 9218903, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30915365

RESUMO

Although thyroid dyshormonogenesis (TDH) accounts for 10-20% of congenital hypothyroidism (CH), the molecular etiology of TDH is unknown in Bangladesh. Thyroid peroxidase (TPO) is most frequently associated with TDH and the present study investigated the spectrum of TPO mutations in Bangladeshi patients and analyzed the effects of mutations on TPO protein structure through in silico approach. Sequencing-based analysis of TPO gene revealed four mutations in 36 diagnosed patients with TDH including three nonsynonymous mutations, namely, p.Ala373Ser, p.Ser398Thr, and p.Thr725Pro, and one synonymous mutation p.Pro715Pro. Homology modelling-based analysis of predicted structures of MPO-like domain (TPO142-738) and the full-length TPO protein (TPO1-933) revealed differences between mutant and wild type structures. Molecular docking studies were performed between predicted structures and heme. TPO1-933 predicted structure showed more reliable results in terms of interactions with the heme prosthetic group as the binding energies were -11.5 kcal/mol, -3.2 kcal/mol, -11.5 kcal/mol, and -7.9 kcal/mol for WT, p.Ala373Ser, p.Ser398Thr, and p.Thr725Pro, respectively, implying that p.Ala373Ser and p.Thr725Pro mutations were more damaging than p.Ser398Thr. However, for the TPO142-738 predicted structures, the binding energies were -11.9 kcal/mol, -10.8 kcal/mol, -2.5 kcal/mol, and -5.3 kcal/mol for the wild type protein, mutant proteins with p.Ala373Ser, p.Ser398Thr, and p.Thr725Pro substitutions, respectively. However, when the interactions between the crucial residues including residues His239, Arg396, Glu399, and His494 of TPO protein and heme were taken into consideration using both TPO1-933 and TPO142-738 predicted structures, it appeared that p.Ala373Ser and p.Thr725Pro could affect the interactions more severely than the p.Ser398Thr. Validation of the molecular docking results was performed by computer simulation in terms of quantum mechanics/molecular mechanics (QM/MM) and molecular dynamics (MD) simulation. In conclusion, the substitutions mutations, namely, p.Ala373Ser, p.Ser398Thr, and p.Thr725Pro, had been involved in Bangladeshi patients with TDH and molecular docking-based study revealed that these mutations had damaging effect on the TPO protein activity.


Assuntos
Autoantígenos/genética , Hipotireoidismo Congênito/genética , Iodeto Peroxidase/genética , Proteínas de Ligação ao Ferro/genética , Mutação/genética , Relação Estrutura-Atividade , Adolescente , Substituição de Aminoácidos/genética , Autoantígenos/química , Bangladesh/epidemiologia , Criança , Pré-Escolar , Simulação por Computador , Hipotireoidismo Congênito/epidemiologia , Hipotireoidismo Congênito/patologia , Feminino , Genótipo , Humanos , Iodeto Peroxidase/química , Proteínas de Ligação ao Ferro/química , Masculino , Modelos Moleculares , Simulação de Acoplamento Molecular , Fenótipo , Glândula Tireoide/metabolismo , Glândula Tireoide/patologia
6.
Dis Model Mech ; 12(1)2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30651277

RESUMO

Pigs share many similarities with humans in terms of anatomy, physiology and genetics, and have long been recognized as important experimental animals in biomedical research. Using an N-ethyl-N-nitrosourea (ENU) mutagenesis screen, we previously identified a large number of pig mutants, which could be further established as human disease models. However, the identification of causative mutations in large animals with great heterogeneity remains a challenging endeavor. Here, we select one pig mutant, showing congenital nude skin and thyroid deficiency in a recessive inheritance pattern. We were able to efficiently map the causative mutation using family-based genome-wide association studies combined with whole-exome sequencing and a small sample size. A loss-of-function variant (c.1226 A>G) that resulted in a highly conserved amino acid substitution (D409G) was identified in the DUOX2 gene. This mutation, located within an exonic splicing enhancer motif, caused aberrant splicing of DUOX2 transcripts and resulted in lower H2O2 production, which might cause a severe defect in thyroid hormone production. Our findings suggest that exome sequencing is an efficient way to map causative mutations and that DUOX2 D409G/D409G mutant pigs could be a potential large animal model for human congenital hypothyroidism.


Assuntos
Processamento Alternativo/genética , Hipotireoidismo Congênito/genética , Oxidases Duais/genética , Éxons/genética , Mutação/genética , Suínos/genética , Animais , Sequência de Bases , Elementos Facilitadores Genéticos/genética , Etilnitrosoureia , Feminino , Genes Recessivos , Estudo de Associação Genômica Ampla , Células HeLa , Homozigoto , Humanos , Peróxido de Hidrogênio/metabolismo , Padrões de Herança/genética , Masculino , Linhagem , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Hormônios Tireóideos/deficiência , Hormônios Tireóideos/metabolismo , Sequenciamento Completo do Exoma
7.
Eur J Endocrinol ; 178(6): 623-633, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29650690

RESUMO

OBJECTIVE: Congenital hypothyroidism (CH), the most common neonatal metabolic disorder, is characterized by impaired neurodevelopment. Although several candidate genes have been associated with CH, comprehensive screening of causative genes has been limited. DESIGN AND METHODS: One hundred ten patients with primary CH were recruited in this study. All exons and exon-intron boundaries of 21 candidate genes for CH were analyzed by next-generation sequencing. And the inheritance pattern of causative genes was analyzed by the study of family pedigrees. RESULTS: Our results showed that 57 patients (51.82%) carried biallelic mutations (containing compound heterozygous mutations and homozygous mutations) in six genes (DUOX2, DUOXA2, DUOXA1, TG, TPO and TSHR) involved in thyroid hormone synthesis. Autosomal recessive inheritance of CH caused by mutations in DUOX2, DUOXA2, TG and TPO was confirmed by analysis of 22 family pedigrees. Notably, eight mutations in four genes (FOXE1, NKX2-1, PAX8 and HHEX) that lead to thyroid dysgenesis were identified in eight probands. These mutations were heterozygous in all cases and hypothyroidism was not observed in parents of these probands. CONCLUSIONS: Most cases of congenital hypothyroidism in China were caused by thyroid dyshormonogenesis rather than thyroid dysgenesis. This study identified previously reported causative genes for 57/110 Chinese patients and revealed DUOX2 was the most frequently mutated gene in these patients. Our study expanded the mutation spectrum of CH in Chinese patients, which was significantly different from Western countries.


Assuntos
Grupo com Ancestrais do Continente Asiático/genética , Hipotireoidismo Congênito/genética , China , Oxidases Duais/genética , Feminino , Fatores de Transcrição Forkhead/genética , Estudos de Associação Genética , Sequenciamento de Nucleotídeos em Larga Escala , Proteínas de Homeodomínio/genética , Humanos , Lactente , Recém-Nascido , Iodeto Peroxidase/genética , Masculino , Proteínas de Membrana/genética , Mutação , Fator de Transcrição PAX8/genética , Linhagem , Receptores da Tireotropina/genética , Análise de Sequência de DNA , Tireoglobulina/genética , Disgenesia da Tireoide/genética , Fator Nuclear 1 de Tireoide/genética , Fatores de Transcrição/genética
8.
Zhongguo Dang Dai Er Ke Za Zhi ; 20(3): 243-250, 2018 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-29530127

RESUMO

Congenital hypothyroidism (CH), which results from insufficient thyroid hormone biosynthesis, is one of the most common neonatal endocrine disorders. Thyroid dysgenesis and thyroid dyshormonogenesis are the two causes of CH and either one will lead to deficiencies of enzymes during thyroid hormone biosynthesis and insufficient thyroid hormone biosynthesis. Recently, researchers have performed extensive studies on genetics of CH. This paper reviews genes reported to be associated with CH in China.


Assuntos
Hipotireoidismo Congênito/genética , Humanos , Iodeto Peroxidase/genética , Proteínas de Membrana/genética , Fator de Transcrição PAX8/genética , Receptores da Tireotropina/genética , Tireoglobulina/genética , Fatores de Transcrição/genética
9.
J Pediatr Endocrinol Metab ; 31(3): 355-359, 2018 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-29425110

RESUMO

BACKGROUND: IGSF1 abnormality causes diverse symptoms, including congenital central hypothyroidism (CCH), prolactin hyposecretion, testicular enlargement and delayed puberty. CASE PRESENTATION: Here, we report a case of a male patient who visited our hospital with a chief complaint of abdominal pain and short stature, in whom we identified a novel IGSF1 mutation. He was closely examined because of chronic constipation since infancy, persistent abdominal pain at 14 years of age and marked short stature (-4.7 standard deviation [SD] for normal Japanese boys). He was diagnosed with CCH. Decreased prolactin (PRL) secretion was also observed. IGSF1 analysis revealed a novel mutation at the splicing donor site (c.2065+1G>A) in intron 11. In silico analysis predicted this mutation to be a non-functional splice donor site. After thyroid hormone replacement, his thyroid function, constipation and growth rate improved. CONCLUSIONS: This is the first report of a patient in whom constipation and short stature led to a diagnosis of CCH with a novel IGSF1 mutation.


Assuntos
Hipotireoidismo Congênito/genética , Imunoglobulinas/genética , Proteínas de Membrana/genética , Mutação/genética , Dor Abdominal , Adolescente , Estatura , Hipotireoidismo Congênito/diagnóstico , Hipotireoidismo Congênito/tratamento farmacológico , Constipação Intestinal , Terapia de Reposição Hormonal , Humanos , Íntrons/genética , Japão , Masculino , Puberdade Tardia/genética , Sítios de Splice de RNA/genética , RNA Mensageiro/genética , Estudos Retrospectivos , Análise de Sequência de DNA , Testículo/crescimento & desenvolvimento , Tiroxina/uso terapêutico
10.
J Hum Genet ; 63(4): 517-520, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29410511

RESUMO

Overgrowth, macrocephaly, accelerated osseous maturation, variable intellectual disability, and characteristic facial features are the main symptoms of Weaver syndrome, a rare condition caused by mutations in EZH2 gene. Recently, in four patients with Weaver-like symptoms without mutations in EZH2 gene, pathogenic variants in EED were described. We present another patient clinically diagnosed with Weaver syndrome in whom WES revealed an EED de novo mutation affecting two neighboring aminoacids, NM_003797.3:c.917_919delinsCGG/p.(Arg306_Asn307delinsThrAsp) located in one allele (in cis). Our observation, together with previous reports suggests that EED gene testing is warranted in patients with the overgrowth syndrome features and suspicion of Weaver syndrome with normal results of EZH2 gene sequencing.


Assuntos
Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/genética , Substituição de Aminoácidos , Hipotireoidismo Congênito/diagnóstico , Hipotireoidismo Congênito/genética , Anormalidades Craniofaciais/diagnóstico , Anormalidades Craniofaciais/genética , Deformidades Congênitas da Mão/diagnóstico , Deformidades Congênitas da Mão/genética , Mutação , Complexo Repressor Polycomb 2/genética , Alelos , Análise Mutacional de DNA , Facies , Humanos , Lactente , Masculino , Fenótipo , Sequenciamento Completo do Exoma
11.
Eur J Med Genet ; 61(7): 393-398, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29477862

RESUMO

Genetic defects of NKX2-1 are classically associated with hypothyroidism, benign chorea and neonatal respiratory distress. The purpose of this study was to identify the genetic pathogenesis of the "NKX2-1 triad" in a 10 year-old female presenting additional features barely described in the disorder. In the neonatal period, she presented with generalized hypotonia and respiratory distress, with later episodes of frequent wheezing. At 3 month-age developmental dysplasia of the hip was diagnosed and at 10 months, primary hypothyroidism was detected and treated. Subsequently, delayed achievement of developmental milestones and then subtle choreic movements of extremities were identified at 2 years of age. Furthermore, delayed teeth eruption and agenesis of some dental pieces, short stature and joint hyperlaxity were also noticed. At 10 years, a poor immune response to polysaccharide antigens and hypogammaglobulinemia, including all IgG subclasses were detected. Surprisingly, no mutations were identified in the complete coding region of NKX2-1 by PCR and Sanger sequencing. MLPA showed a de novo loss of gene dosage in all 3 probes located in NKX2-1 exons. A CGH-array identified a deletion of 3.32 Mb in chromosome 14q13.2-q21.1 containing 20 genes, including NKX2-1, PAX9 and two candidate genes (NFKB1A and PPP2R3C) involved in immune response. The Brain-Lung-Thyroid syndrome (OMIM#610978; ORPHA:209905) associated with other clinical phenotypes should suggest monoallelic deletions of chromosome 14 causing haploinsufficiency of NKX2-1, and other contiguous genes like PAX9 (hypodontia) or other dosage-sensitive genes in the chromosomal vicinity that emerge as candidates for hypogammaglobulinemia, mainly NFKBIA.


Assuntos
Atetose/genética , Coreia/genética , Cromossomos Humanos Par 14/genética , Hipotireoidismo Congênito/genética , Síndromes de Imunodeficiência/genética , Síndrome do Desconforto Respiratório do Recém-Nascido/genética , Criança , Deleção Cromossômica , Feminino , Humanos , Fenótipo
12.
J Clin Endocrinol Metab ; 103(3): 839-852, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29294041

RESUMO

Context: Identification of a frameshift heterozygous mutation in the transcription factor NKX2-1 in a patient with brain-lung-thyroid syndrome (BLTS) and life-threatening lung emphysema. Objective: To study the genetic defect that causes this complex phenotype and dissect the molecular mechanism underlying this syndrome through functional analysis. Methods: Mutational study by DNA sequencing, generation of expression vectors, site-directed mutagenesis, protein-DNA-binding assays, luciferase reporter gene assays, confocal microscopy, coimmunoprecipitation, and bioinformatics analysis. Results: We identified a mutation [p.(Val75Glyfs*334)] in the amino-terminal domain of the NKX2-1 gene, which was functionally compared with a previously identified mutation [p.(Ala276Argfs*75)] in the carboxy-terminal domain in other patients with BLTS but without signs of respiratory distress. Both mutations showed similar protein expression profiles, subcellular localization, and deleterious effects on thyroid-, brain-, and lung-specific promoter activity. Coexpression of the coactivator TAZ/WWTR1 (transcriptional coactivator with PDZ-binding motif/WW domain-containing transcription regulator protein 1) restored the transactivation properties of p.(Ala276Argfs*75) but not p.(Val75Glyfs*334) NKX2-1 on a lung-specific promoter, although both NKX2-1 mutants could interact equally with TAZ/WWTR1. The retention of residual transcriptional activity in the carboxy-terminal mutant, which was absent in the amino-terminal mutant, allowed the functional rescue by TAZ/WWTR1. Conclusions: Our results support a mechanistic model involving TAZ/WWTR1 in the development of human congenital emphysema, suggesting that this protein could be a transcriptional modifier of the lung phenotype in BLTS.


Assuntos
Atetose/genética , Coreia/genética , Hipotireoidismo Congênito/genética , Mutação da Fase de Leitura , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Síndrome do Desconforto Respiratório do Recém-Nascido/genética , Fator Nuclear 1 de Tireoide/genética , Fatores de Transcrição/fisiologia , Análise Mutacional de DNA/métodos , Seguimentos , Humanos , Recém-Nascido , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Enfisema Pulmonar/congênito , Enfisema Pulmonar/genética , Fatores de Transcrição/genética
13.
Clin Chim Acta ; 476: 38-43, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29146476

RESUMO

OBJECTIVES: Defects in the human GLI-similar 3 (GLIS3) gene are reported to be a rare cause of congenital hypothyroidism (CH) and neonatal diabetes. The aim of this study was to examine the prevalence of GLIS3 mutation among CH patients in the Guangxi Zhuang Autonomous Region of China and to define the relationships between GLIS3 genotypes and clinical phenotypes. METHODS: Blood samples were collected from 592 patients with CH in Guangxi Zhuang Autonomous Region, China, and genomic DNA was extracted from peripheral blood leukocytes. All exons of the GLIS3 gene with their exon-intron boundaries were screened by next-generation sequencing (NGS) and CNVplex®. Chromosomal microarray analysis (CMA) was performed to detect the existence of the adjacent gene deletion. RESULTS: NGS and CNVplex® analysis of GLIS3 in 592 CH patients revealed two different variations in two individuals (2/592, 0.3%). Patient 1 was the paternal allele of 9p24.3p23 heterozygous deletion including the whole GLIS3 gene, and patient 2 was heterozygous for c.2159G>A (p.R720Q) GLIS3 variant combined with compound heterozygous DUOX2 mutations (p.R683L/p.L1343F). CONCLUSIONS: Our study indicated that the prevalence of GLIS3 variations was 0.3% among studied Chinese CH patients. Multiple variations in one or more CH associated genes can be found in one patient. We found a novel GLIS3 variation c.2159G>A (p.R720Q), thereby expanding the variation spectrum of the gene.


Assuntos
Hipotireoidismo Congênito/genética , Fatores de Transcrição/genética , Pré-Escolar , China , Estudos de Coortes , Hipotireoidismo Congênito/sangue , Hipotireoidismo Congênito/diagnóstico , Humanos , Lactente , Recém-Nascido , Mutação , Fatores de Transcrição/sangue
14.
Exp Clin Endocrinol Diabetes ; 126(2): 85-90, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28954305

RESUMO

OBJECTIVE: To elucidate the molecular mechanism which causes thyroid dysgenesis (TD) in a boy with brain-lung-thyroid syndrome. DESIGN, PATIENTS, MEASUREMENTS: We describe a patient with TD, respiratory disease and cerebral palsy who is heterozygous for mutations in two different genes, the PAX8 (p.E234K) and the NKX2.1 (p.A329GfsX108). In vitro studies were performed to functionally characterize these mutations. Congenital hypothyroidism (CH) was identified by neonatal screening associated with a hypoplastic thyroid gland. Postpartum he developed a brain-lung-thyroid syndrome with severe respiratory failure, symptomatic epilepsy and a considerable psychomotor retardation. The DNA-binding capability and the transcriptional activity of the two mutated transcription factors were investigated in vitro. RESULTS: The NKX2.1 mutation did not show any transcriptional activity and had almost no DNA-binding. The PAX8 mutation was normally located to the nucleus and showed a normal transactivation and a normal binding to the known downstream targets. CONCLUSIONS: The molecular defect explaining the phenotype of brain-lung-thyroid syndrome was identified. To what extent the PAX8 mutation contributes to the phenotype needs to be further investigated. We recommend to screen patients with CH and TD for mutations in all known TD candidate genes.


Assuntos
Atetose/genética , Coreia/genética , Hipotireoidismo Congênito/genética , Fator de Transcrição PAX8/genética , Síndrome do Desconforto Respiratório do Recém-Nascido/genética , Fator Nuclear 1 de Tireoide/genética , Criança , Humanos , Masculino , Mutação
15.
Eur J Endocrinol ; 178(2): 137-144, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29092890

RESUMO

OBJECTIVE: Biallelic TSHR mutations cause congenital hypothyroidism (CH). Serum TSH levels of monoallelic mutation carriers range from normal to mildly elevated, and thus the size of its effect remains unclear. The objectives were to examine the association between monoallelic TSHR mutations and positivity at newborn screening (NBS) for CH, and to test whether the association was modified by another genetic factor. SUBJECTS AND METHODS: We enrolled 395 patients that had a positive result in NBS and sequenced TSHR. Monoallelic TSHR mutation carriers were further sequenced for DUOX2. Molecular functions of the mutations were verified in vitro. The frequency of the mutations in the study subjects was compared with a theoretical value in the Japanese general population. Odds ratio (OR) for NBS positivity associated with the mutation was calculated. Using Bayes' theorem, we estimated a posterior probability of NBS positivity given the mutation. RESULTS: Twenty-six monoallelic TSHR mutation carriers were found. Four out of the 26 also had a monoallelic DUOX2 mutation (double heterozygotes). The frequencies of monoallelic TSHR mutation carriers (6.6%) and double heterozygotes (1.0%) were significantly higher than those in the general population (0.58% and 0.0087%, respectively). OR for NBS positivity of having a monoallelic TSHR mutation or being a double heterozygote was 12.0 or 117.9, respectively. Posterior probability of NBS positivity was 0.38% in monoallelic TSHR mutation carriers and 3.8% in double heterozygotes. CONCLUSIONS: Monoallelic TSHR mutations are significantly associated with NBS positivity, and the association is further strengthened by the coexistence of monoallelic DUOX2 mutations.


Assuntos
Hipotireoidismo Congênito/genética , Oxidases Duais/genética , Receptores da Tireotropina/genética , Grupo com Ancestrais do Continente Asiático/genética , Teorema de Bayes , Feminino , Heterozigoto , Humanos , Técnicas In Vitro , Recém-Nascido , Japão , Masculino , Mutação , Triagem Neonatal , Razão de Chances , Análise de Sequência de DNA
16.
J Clin Endocrinol Metab ; 103(4): 1470-1478, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29244146

RESUMO

Context: Weaver syndrome is characterized by tall stature, advanced bone age, characteristic facies, and variable intellectual disability. It is caused by heterozygous mutations in enhancer of zeste homolog 2 (EZH2), a histone methyltransferase responsible for histone H3 at lysine 27 (H3K27) trimethylation. However, no early truncating mutations have been identified, suggesting that null mutations do not cause Weaver syndrome. Objective: To test alternative hypotheses that EZH2 variants found in Weaver syndrome cause either a gain of function or a partial loss of function. Design: Exome sequencing was performed in a boy with tall stature, advanced bone age, and mild dysmorphic features. Mutant or wild-type EZH2 protein was expressed in mouse growth plate chondrocytes with or without endogenous EZH2, and enzymatic activity was measured. A mouse model was generated, and histone methylation was assessed in heterozygous and homozygous embryos. Results: A de novo missense EZH2 mutation [c.1876G>A (p.Val626Met)] was identified in the proband. When expressed in growth plate chondrocytes, the mutant protein showed decreased histone methyltransferase activity. A mouse model carrying this EZH2 mutation was generated using CRISPR/Cas9. Homozygotes showed perinatal lethality, whereas heterozygotes were viable, fertile, and showed mild overgrowth. Both homozygous and heterozygous embryos showed decreased H3K27 methylation. Conclusion: We generated a mouse model with the same mutation as our patient, found that it recapitulates the Weaver overgrowth phenotype, and demonstrated that EZH2 mutations found in Weaver syndrome cause a partial loss of function.


Assuntos
Anormalidades Múltiplas/genética , Hipotireoidismo Congênito/genética , Anormalidades Craniofaciais/genética , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Deformidades Congênitas da Mão/genética , Histona-Lisina N-Metiltransferase/metabolismo , Mutação , Animais , Criança , Exoma , Histona Metiltransferases , Humanos , Masculino , Camundongos
18.
Blood ; 130(20): 2161-2170, 2017 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-28972010

RESUMO

Congenital hypothyroidism (CH) is one of the most prevalent endocrine diseases, for which the underlying mechanisms remain unknown; it is often accompanied by anemia and immunodeficiency in patients. Here, we created a severe CH model together with anemia and T lymphopenia to mimic the clinical features of hypothyroid patients by ethylnitrosourea (ENU) mutagenesis in Bama miniature pigs. A novel recessive c.1226A>G transition of the dual oxidase 2 (DUOX2) gene was identified as the causative mutation. This mutation hindered the production of hydrogen peroxide (H2O2) and thus contributed to thyroid hormone (TH) synthesis failure. Transcriptome sequencing analysis of the thymuses showed that Krüppel-like factor 9 (KLF9) was predominantly downregulated in hypothyroid mutants. KLF9 was verified to be directly regulated by TH in a TH receptor (TR)-dependent manner both in vivo and in vitro. Furthermore, knockdown of klf9 in zebrafish embryos impaired hematopoietic development including erythroid maturation and T lymphopoiesis. Our findings suggest that the TR-KLF9 axis is responsible for the hematopoietic dysfunction and might be exploited for the development of novel therapeutic interventions for thyroid diseases.


Assuntos
Hipotireoidismo Congênito/fisiopatologia , Modelos Animais de Doenças , Hematopoese , Fatores de Transcrição Kruppel-Like/metabolismo , Receptores dos Hormônios Tireóideos/metabolismo , Suínos , Hormônios Tireóideos/fisiologia , Animais , Hipotireoidismo Congênito/genética , Oxidases Duais/genética , Etilnitrosoureia , Regulação da Expressão Gênica , Genes Recessivos , Peróxido de Hidrogênio/metabolismo , Redes e Vias Metabólicas , Mutagênese Sítio-Dirigida , Mutação , Timo , Sequenciamento Completo do Exoma , Peixe-Zebra , Proteínas de Peixe-Zebra/metabolismo
19.
Clin Genet ; 92(5): 561-562, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28940199

RESUMO

Identification of this additional patient from a distant part of the originally described pedigree (Synofzik et al. 2014) confirms pathogenicity of DNAJC3 mutations. Hypothyroidism is a newly identified feature in addition to the known phenotype (diabetes with multisystemic neurodegeneration).


Assuntos
Hipotireoidismo Congênito/complicações , Hipotireoidismo Congênito/genética , Diabetes Mellitus/genética , Proteínas de Choque Térmico HSP40/genética , Mutação/genética , Degeneração Neural/complicações , Degeneração Neural/genética , Feminino , Humanos , Masculino , Linhagem , Fenótipo , Adulto Jovem
20.
Endocr J ; 64(11): 1087-1097, 2017 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-28867693

RESUMO

Thyroid peroxidase (TPO) deficiency, caused by biallelic TPO mutations, is a well-established genetic form of congenital hypothyroidism (CH). More than 100 patients have been published, and the patients have been diagnosed mostly in the frame of newborn screening (NBS) programs. Correlation between clinical phenotypes and TPO activity remains unclear. Here, we report clinical and molecular findings of two unrelated TPO mutation-carrying mildly hypothyroid patients. The two patients were born at term after an uneventful pregnancy and delivery, and were NBS negative. They sought medical attention due to goiter at age 8 years. Evaluation of the thyroid showed mild elevation of serum TSH levels, normal or slightly low serum T4 levels, high serum T3 to T4 molar ratio, high serum thyroglobulin levels, and high thyroidal 123I uptake. We performed next-generation sequencing-based genetic screening, and found that one patient was compound heterozygous for two novel TPO mutations (p.Asp224del; c.820-2A>G), and the other was homozygous for a previously known mutation (p.Trp527Cys). In vitro functional analyses using HEK293 cells showed that the two amino acid-altering mutations (p.Asp224del and p.Trp527Cys) caused partial loss of the enzymatic activity. In conclusion, we report that TPO mutations with residual activity are associated with mild TPO deficiency, which is clinically characterized by marked goiter, mild TSH elevation, high serum T3 to T4 molar ratio, and high serum thyroglobulin levels. Our findings illuminate the hitherto under-recognized correlation between clinical phenotypes and residual enzymatic activity among patients with TPO deficiency.


Assuntos
Autoantígenos/genética , Autoantígenos/metabolismo , Hipotireoidismo Congênito/genética , Hipotireoidismo Congênito/metabolismo , Iodeto Peroxidase/deficiência , Proteínas de Ligação ao Ferro/genética , Proteínas de Ligação ao Ferro/metabolismo , Mutação , Criança , Hipotireoidismo Congênito/diagnóstico , Hipotireoidismo Congênito/patologia , Análise Mutacional de DNA , Feminino , Estudos de Associação Genética , Testes Genéticos , Células HEK293 , Humanos , Recém-Nascido , Iodeto Peroxidase/genética , Iodeto Peroxidase/metabolismo , Masculino , Triagem Neonatal , Linhagem , Fenótipo , Índice de Gravidade de Doença
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