RESUMO
Biallelic loss-of-function variants in the IYD gene cause hypothyroidism resulting from iodine wasting. We describe 8 patients (from 4 families in which the parents are first cousins) who are homozygous for a variant in IYD (including a novel missense deleterious variant, c.791C>T [P264L], in 1 family). Seven patients presented between 5 and 16 years of age with a large goiter, overt hypothyroidism, and a high serum thyroglobulin. The goiter subsided with levothyroxine therapy in most. Upon stopping levothyroxine in 5 patients, goiter and hypothyroidism reappeared in 3. In these 3 patients, a rising serum thyroglobulin concentration preceded hypothyroidism and goiter and urinary iodine excretion was low. In patients who remained euthyroid, urinary iodine was normal. In conclusion, these patients bearing biallelic pathogenic variants in IYD developed a large goiter, a high serum thyroglobulin, and overt hypothyroidism when their iodine intake was low.
Assuntos
Bócio , Hipotireoidismo , Linhagem , Tiroxina , Humanos , Feminino , Masculino , Adolescente , Hipotireoidismo/genética , Criança , Pré-Escolar , Tiroxina/uso terapêutico , Bócio/genética , Tireoglobulina/genética , Iodo/deficiência , Alelos , Mutação de Sentido Incorreto , SimportadoresRESUMO
Iodine deficiency-induced goiter continues to be a global public health concern, with varying manifestations based on geography, patient's age, and sex. To gain insights into clinical occurrences, a retrospective study analyzed medical records from patients with iodine deficiency-induced goiter or thyroid cancer who underwent surgery at the Community Hospital in Riehen, Switzerland, between 1929 and 1989. Despite today's adequate iodine supplementation, a significant risk for iodine-independent goiter remains in Switzerland, suggesting that genetic factors, among others, might be involved. Thus, a pilot study exploring the feasibility of genetic analysis of blood spots from these medical records was conducted to investigate and enhance the understanding of goiter development, potentially identify genetic variations, and explore the influence of dietary habits and other environmental stimuli on the disease.Blood prints from goiter patients' enlarged organs were collected per decade from medical records. These prints had been made by pressing, drawing, or tracing (i.e., pressed and drawn) the removed organs onto paper sheets. DNA analysis revealed that its yields varied more between the prints than between years. A considerable proportion of the samples exhibited substantial DNA degradation unrelated to sample collection time and DNA mixtures of different contributors. Thus, each goiter imprint must be individually evaluated and cannot be used to predict the success rate of genetic analysis in general. Collecting a large sample or the entire blood ablation for genetic analysis is recommended to mitigate potential insufficient DNA quantities. Researchers should also consider degradation and external biological compounds' impact on the genetic analysis of interest, with the dominant contributor anticipated to originate from the patient's blood.
Assuntos
Bócio , Iodo , Neoplasias da Glândula Tireoide , Humanos , Suíça , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/sangue , Bócio/genética , Bócio/sangue , Iodo/deficiência , Masculino , Feminino , Alemanha , História do Século XX , Estudos Retrospectivos , Pessoa de Meia-Idade , AdultoRESUMO
BACKGROUND: In this study, we used targeted next-generation sequencing (NGS) to investigate the genetic basis of congenital hypothyroidism (CH) in a 19-year-old Tunisian man who presented with severe hypothyroidism and goiter. CASE PRESENTATION: The propositus reported the appearance of goiter when he was 18. Importantly, he did not show signs of mental retardation, and his growth was proportionate. A partial organification defect was detected through the perchlorate-induced iodide discharge test. NGS identified a novel homozygous mutation in exon 18 of the SLC26A7 gene (P628Qfs*11), which encodes for a new iodide transporter. This variant is predicted to result in a truncated protein. Notably, the patient's euthyroid brother was heterozygous for the same mutation. No renal acid-base abnormalities were found and the administration of 1 mg of iodine failed to correct hypothyroidism. CONCLUSIONS: We described the first case of goitrous CH due to a homozygous mutation of the SLC26A7 gene diagnosed during late adolescence.
Assuntos
Hipotireoidismo Congênito , Homozigoto , Mutação , Transportadores de Sulfato , Humanos , Masculino , Antiporters , Hipotireoidismo Congênito/genética , Hipotireoidismo Congênito/diagnóstico , Bócio/genética , Transportadores de Sulfato/genética , AdolescenteRESUMO
We report the case of a paediatric female patient affected by Bannayan-Riley-Ruvalcaba syndrome (BRRS) and congenital hypothyroidism (CH) with homozygous mutation of the TPO gene. She underwent total thyroidectomy at the age of seven years because of the development of a multinodular goiter. BRRS patients present an increased risk of benign and malignant thyroid disease since childhood because of inactivating mutation of PTEN, an onco-suppressor gene. Instead, homozygous mutations in the TPO gene can be associated with severe forms of hypothyroidism with goiter; previous studies have described cases of follicular and papillary thyroid cancer in CH patients with TPO mutation despite a perfectly controlled thyroid function with Levothyroxine therapy. To our knowledge, this is the first case that describes the possible synergic role of coexisting mutation of both TPO and PTEN in the development of multinodular goiter underlining the importance of a tailored surveillance program in these patients, especially during childhood.
Assuntos
Hipotireoidismo Congênito , Bócio , Síndrome do Hamartoma Múltiplo , Neoplasias da Glândula Tireoide , Humanos , Criança , Feminino , Síndrome do Hamartoma Múltiplo/complicações , Síndrome do Hamartoma Múltiplo/genética , Síndrome do Hamartoma Múltiplo/patologia , Hipotireoidismo Congênito/complicações , Hipotireoidismo Congênito/genética , Mutação , Bócio/complicações , Bócio/genética , Bócio/cirurgia , PTEN Fosfo-Hidrolase/genéticaRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Haizao Yuhu decoction (HYD) is a classic Chinese herbal formula described in the surgical monographs of the Ming Dynasty "Waikezhengzong." It has been widely used to treat goiter for approximately 500 years and found to be particularly effective. HYD contains glycyrrhiza and sargassum. This pair of herbs belongs to "18 incompatible medicaments" of traditional Chinese medicine theory. Although these two herbs are opposite, our preliminary study proved that they have superior effect when added into HYD at 2 times the dose of Chinese Pharmacopoeia. However, the species of glycyrrhiza in HYD that are the most effective have not been recorded in ancient Chinese medical texts. According to the Chinese Pharmacopoeia, glycyrrhiza is divided into the following three species: Glycyrrhiza uralensis Fish., G. glabra L., and G. inflata Bat. The effect of HYD containing different species of glycyrrhiza and their mechanisms remain to be further explored. AIM OF THE STUDY: To investigate the effect of HYD containing three species of glycyrrhiza on goiter, and to elucidate the molecular mechanism using network pharmacology combined with RNA sequencing (RNA-seq). MATERIALS AND METHODS: A rat model of goiter was established by 14 days of intragastric gavage of propylthiouracil (PTU), and the rats were treated for 4 weeks with HYD containing three different species of glycyrrhiza. The body weight and rectal temperature of rats were tested weekly. At the end of the experiment, the serum and thyroid tissues of rats were collected. The effect of the three HYDs was assessed based on general observations (including body weight, rectal temperature, and living status of rats), absolute/relative thyroid weight, thyroid function (including triiodothyronine, thyroxine, free triiodothyronine, free thyroxine, and thyroid-stimulating hormone levels), and thyroid tissue pathology. Next, we explored their pharmacological mechanisms using network pharmacology combined with RNA-seq and validated key targets using real-time quantitative reverse-transcription polymerase chain reaction (RT-qPCR), western blotting (WB), and immunofluorescence (IF) assays. RESULTS: The three HYDs reduced the absolute/relative weights of thyroid tissues and improved the pathological structure, thyroid function, and general findings of rats with goiter. Overall, the effect of HYD-G. uralensis Fish. (HYD-U) was better. Results from network pharmacology and RNA-seq jointly suggested that both the pathogenesis of goiter and the mechanism of action of HYD for goiter were related to the phosphatidylinositol 3-kinase-protein kinase B (PI3K-Akt) pathway. We validated the key targets in the pathway, namely, vascular endothelial growth factor (VEGF) A, VEGF receptor 2, phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) and its encoded protein PI3K (p85), AKT serine/threonine kinase 1 (AKT1), phospho-AKT and cyclin D1 using RT-qPCR, WB, and IF assays. The PI3K-Akt pathway was hyperactivated in rats with PTU-induced goiter, whereas the three HYDs could inhibit the pathway. CONCLUSION: This study confirmed the definite effect of the three HYDs in the treatment of goiter, and HYD-U was found to be more effective. The three HYDs inhibited angiogenesis and cell proliferation in goiter tissue by inhibiting the PI3K-Akt signaling pathway.
Assuntos
Medicamentos de Ervas Chinesas , Glycyrrhiza , Bócio , Ratos , Animais , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fosfatidilinositol 3-Quinases/genética , Tri-Iodotironina , Tiroxina , Farmacologia em Rede , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Medicamentos de Ervas Chinesas/química , Glycyrrhiza/química , Bócio/tratamento farmacológico , Bócio/genética , Análise de Sequência de RNA , Peso CorporalRESUMO
Congenital hypothyroidism (CH) due to thyroglobulin (TG) variants causes very low serum TG levels with normal or enlarged thyroid glands, depending on the severity of the defect, and with autosomal recessive inheritance. The purpose of this study was to functionally characterize p.Cys1281Tyr variant in the TG gene in order to increase our knowledge of the molecular mechanisms associated with CH. In order to find evidence that support the hypothesis that the p.Cys1281Tyr variant would affect the TG folding were performed amino acid prediction, 3D modeling and transient expression analysis in HEK293T cells. 18 of the 21â³in silico" algorithms predict a deleterious effect of the p.Cys1281Tyr variant. The full-length 3D model p.Cys1281Tyr TG showed disulfide bond cleavage between the cysteines at positions 1249 and 1281 and rearrangement of the TG structure, while transient expression analysis indicated that p.Cys1281Tyr causes retention of the protein inside the cell. Consequently, these results show that this pathogenic variant makes it impossible for TG to fulfill its function in the biosynthesis process of thyroid hormones, causing CH. In conclusion, our results confirm the pathophysiological importance of misfolding of TG as a consequence of p.Cys1281Tyr variant located in the hinge module/flap region of TG.
Assuntos
Hipotireoidismo Congênito , Bócio , Humanos , Hipotireoidismo Congênito/genética , Tireoglobulina/genética , Tireoglobulina/metabolismo , Células HEK293 , Bócio/genética , Hormônios TireóideosRESUMO
Objective: Guidelines on congenital hypothyroidism (CH) recommend that genetic testing should aim to improve diagnosis, treatment or prognosis, but it is unclear which patients would benefit most from the genetic investigation. We aimed to investigate the genetic etiology of transient CH (TCH) and permanent CH (PCH) in a well-characterized cohort, and thereby evaluate the impact of genetic testing on the management and prognosis of children with CH. Methods: A total of 48 CH patients with normal, goitrous (n 5) or hypoplastic thyroid (n 5) were studied by high-throughput sequencing using a custom-designed 23-gene panel. Patients initially categorized as TCH (n 15), PCH (n 26) and persistent hyperthyrotropinemia (PHT, n 7) were re-evaluated after genetic testing. Results: Re-evaluation based on genetic testing changed the initial diagnoses from PCH to PHT (n 2) or TCH (n 3) and from PHT to TCH (n 5), which resulted in a final distribution of TCH (n 23), PCH (n 21) and PHT (n 4). Genetic analysis also allowed us to discontinue treatment in five patients with monoallelic TSHR or DUOX2, or no pathogenic variants. The main reasons for changes in diagnosis and treatment were the detection of monoallelic TSHR variants and the misdiagnosis of thyroid hypoplasia on neonatal ultrasound in low birthweight infants. A total of 41 (35 different, 15 novel) variants were detected in 65% (n 31) of the cohort. These variants, which most frequently affected TG, TSHR and DUOX2, explained the genetic etiology in 46% (n 22) of the patients. The molecular diagnosis rate was significantly higher in patients with PCH (57%, n 12) than TCH (26%, n 6). Conclusions: Genetic testing can change diagnosis and treatment decisions in a small proportion of children with CH, but the resulting benefit may outweigh the burden of lifelong follow-up and treatment.
Assuntos
Hipotireoidismo Congênito , Bócio , Recém-Nascido , Lactente , Humanos , Criança , Hipotireoidismo Congênito/diagnóstico , Oxidases Duais/genética , Testes Genéticos , Bócio/genética , Triagem Neonatal/métodosRESUMO
Congenital hypothyroidism with biallelic thyroglobulin (Tg protein, encoded by the TG gene) mutation is an endoplasmic reticulum (ER) storage disease. Many patients (and animal models) grow an enlarged thyroid (goiter), yet some do not. In adulthood, hypothyroid TGcog/cog mice (bearing a Tg-L2263P mutation) exhibit a large goiter, whereas adult WIC rats bearing the TGrdw/rdw mutation (Tg-G2298R) exhibit a hypoplastic thyroid. Homozygous TG mutation has been linked to thyroid cell death, and cytotoxicity of the Tg-G2298R protein was previously thought to explain the lack of goiter in WIC-TGrdw/rdw rats. However, recent studies revealed that TGcog/cog mice also exhibit widespread ER stress-mediated thyrocyte death, yet under continuous feedback stimulation, thyroid cells proliferate in excess of their demise. Here, to examine the relative proteotoxicity of the Tg-G2298R protein, we have used CRISPR-CRISPR-associated protein 9 technology to generate homozygous TGrdw/rdw knock-in mice in a strain background identical to that of TGcog/cog mice. TGrdw/rdw mice exhibit similar phenotypes of defective Tg protein folding, thyroid histological abnormalities, hypothyroidism, and growth retardation. TGrdw/rdw mice do not show evidence of greater ER stress response or stress-mediated cell death than TGcog/cog mice, and both mouse models exhibit sustained thyrocyte proliferation, with comparable goiter growth. In contrast, in WIC-TGrdw/rdw rats, as a function of aging, the thyrocyte proliferation rate declines precipitously. We conclude that the mutant Tg-G2298R protein is not intrinsically more proteotoxic than Tg-L2263P; rather, aging-dependent difference in maintenance of cell proliferation is the limiting factor, which accounts for the absence of goiter in adult WIC-TGrdw/rdw rats.
Assuntos
Bócio , Hipotireoidismo , Tireoglobulina , Glândula Tireoide , Animais , Proliferação de Células , Bócio/congênito , Bócio/genética , Bócio/metabolismo , Hipotireoidismo/genética , Hipotireoidismo/metabolismo , Camundongos , Ratos , Tireoglobulina/genética , Glândula Tireoide/fisiopatologiaRESUMO
Background: Multinodular goiter (MNG) is the most common disorder of the thyroid gland. Aging and genetic mutations that impair thyroid hormone (TH) production have been implicated in the development of MNG. XB130 is an adaptor/scaffold protein predominantly expressed in the thyroid gland. XB130 deficiency leads to transient postnatal growth retardation in mice due to congenital hypothyroidism. We studied the formation of MNG and possible mechanisms in elderly mice. Methods: Thyroid glands of male and female Xb130-knockout (Xb130-/-), heterozygous (Xb130+/-), and wild-type (Xb130+/+) mice at the ages of 12-20 months were harvested for visual examination, histopathological, and immunohistological analyses. Blood and thyroid samples were collected after feeding elderly mice with a low iodine diet for 125I uptake and perchlorate discharge assay. The activity of thyroperoxidase (Tpo) was examined by spectrophotometric evaluation of iodide oxidation. Results: While moderate MNG was seen in Xb130+/+ and Xb130+/- mice, severe MNG, characterized by multiple nodules intermixed with dilated colloid-rich macrofollicles, was found only in Xb130-/- mice at 18 months. Thyrocyte cytoskeletal structure and cell adhesion molecules were disorganized, and TH production was significantly reduced. Reduced iodide organification was seen in elderly Xb130+/+ mice and further enhanced in Xb130-/- mice. In Xb130+/+ mice, Tpo shows high affinity with hydrogen peroxide (H2O2) throughout aging, but reduced affinity with iodide in an age-dependent manner. By contrast, in elderly Xb130-/- mice, the affinity of Tpo for iodide remained high, but the affinity of Tpo for H2O2 was reduced. Conclusions: The pathophysiological features in the thyroid glands of aged Xb130-/- mice closely resemble the features of MNG in humans. Moderate MNG in elderly mice was dramatically aggravated by XB130 deficiency. Reduced affinity of Tpo for H2O2 may contribute to MNG development via oxidative stress. This could be specific to XB130 deficiency but also could be a common mechanism in MNG. Its clinical relevance should be further investigated.
Assuntos
Hipotireoidismo Congênito , Bócio , Idoso , Animais , Hipotireoidismo Congênito/genética , Feminino , Bócio/genética , Bócio/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Iodeto Peroxidase/genética , Iodeto Peroxidase/metabolismo , Iodetos/metabolismo , Masculino , Camundongos , Hormônios TireóideosRESUMO
Congenital hypothyroidism (CH) due to dyshormonogenesis may occur due to mutations in any of the key genes involved in thyroid hormone biosynthesis (TG, TPO, DUOX2, DUOXA2, SLC5A5, IYD, SLC26A4 and SLC26A7). Mutations in the thyroglobulin gene (TG) are frequently associated with goiter, which may present fetally or neonatally, although a spectrum of phenotypes is reported. We present the case of a woman of Eritrean origin who presented in the third trimester of pregnancy in the early stages of labor. Ultrasound at presentation revealed a fetal neck swelling consistent with a goiter. Following delivery by Caesarian section with minimal respiratory support, the infant was found to be hypothyroid with undetectable serum levels of thyroglobulin. Sequencing of the TG revealed a homozygous donor splice site pathogenic variant (c.5686+1delG) not previously described in the literature. Levothyroxine treatment resulted in normal growth and psychomotor development. Goitrous CH with inappropriately low thyroglobulin has previously been reported in patients harbouring homozygous single nucleotide substitutions at the same TG donor splice site, which result in exon skipping and retention of malformed thyroglobulin by the endoplasmic reticulum. We conclude that the TG c.5686+1delG pathogenic variant is the likely basis for our patient's fetal goiter and CH, and that the clinical phenotype associated with TG c.5686+1delG is comparable to that seen with single nucleotide substitutions at the same site.
Assuntos
Hipotireoidismo Congênito , Doenças Fetais , Bócio , Hipotireoidismo Congênito/genética , Eritreia , Feminino , Bócio/genética , Humanos , Mutação , Nucleotídeos , Tireoglobulina/genéticaRESUMO
The hypothalamic-pituitary-thyroid (HPT) axis regulates many critical features in vertebrates. Utilizing TALENs and CRISPR/Cas9 techniques, thyroid-stimulating hormone subunit beta a (tshba), thyroglobulin (tg), and solute carrier family 16 member 2 (slc16a2) mutant zebrafish lines were generated. Among the three mutants, the earliest time point for the significantly altered T3 contents was observed in tshba mutants, which resulted in the most severe defects, including typical defects such as the retardation of inflated anterior swimming bladder (aSB), proper formation of fin ray and posterior squamation (SP), the larval-to-juvenile transition (LTJT) process, juvenile growth retardation, and mating failure. In tg mutants, which are actually compensated with an alternative splicing form, growth retardation was observed in the juvenile stage without LTJT and reproductive defects. The evident goiter phenotype was only observed in tg- and slc16a2 mutants, but not in tshba mutants. Other than goiters being observed, no other significant developmental defects were found in the slc16a2 mutants. Regarding the reproductive defects observed in tshba mutants, the defective formation of the secondary sex characteristics (SSCs) was observed, while no obvious alterations during gonad development were found. Based on our analyses, zebrafish at the 6-12 mm standard length or 16-35 days post-fertilization (dpf) should be considered to be in their LTJT phase. Using a series of zebrafish dyshormonogenesis models, this study demonstrated that the TSH function is critical for the proper promotion of zebrafish LTJT and SSC formation. In addition, the elevation of TSH levels appears to be essential for goiter appearance in zebrafish.
Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Morfogênese/genética , Tireotropina Subunidade beta/genética , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/genética , Animais , Sequência de Bases , Bócio/genética , Bócio/metabolismo , Hipotireoidismo/genética , Hipotireoidismo/metabolismo , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Transportadores de Ácidos Monocarboxílicos/genética , Transportadores de Ácidos Monocarboxílicos/metabolismo , Mutação , Fenótipo , Reprodução/genética , Tireoglobulina/genética , Tireoglobulina/metabolismo , Tireotropina Subunidade beta/metabolismo , Tri-Iodotironina/metabolismo , Peixe-Zebra/crescimento & desenvolvimento , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/metabolismoRESUMO
Introduction: It is rare for a euthyroid mother to carry a child with a fetal goiter. However, cases of congenital hypothyroidism (CH) caused by thyroid dyshormonogenesis have been reported. Even though gene mutations associated with fetal goiter have been reported in a few studies, the effects on intellectual development have not been investigated. This study aimed to characterize and investigate the underlying genetic mechanism of CH and neuropsychological development and growth of two siblings with CH-induced fetal goiters. Case report: Two male siblings from a non-consanguineous marriage with CH and fetal goiter were diagnosed by ultrasonography at 32- and 26-weeks of gestation. This condition was confirmed by cordocentesis in the first pregnancy (TSH: 135 µIU/ml). The mother was euthyroid, and no intra-amniotic levothyroxine treatment was performed. Peripheral blood DNA was screened for TPO mutations. The new deletion p.Cys296Alafs*21 and the p.Arg665Trp mutation, inherited from heterozygous parents, were identified in both patients. Functional analysis showed both mutations reduced the TPO enzyme activity and impaired the membrane localization. The p.Cys296Alafs*21 mutation produces a protein product with a drastically reduced molecular weight. Additionally, a complete clinical and neuropsychological evaluation was also performed. The WISC IV test was employed to provide an overall measure of the siblings' cognitive and intellectual abilities. No growth retardation was detected in either child. In general, both children showed normal neuropsychological development; however, they exhibited slight reduction of Processing Speed Index scores, which are sensitive to neurological and attentional factors and motor maturation activity. Notably, the younger sibling obtained significantly low scores in the Operational Memory Index, a measure of attention capacity and psychoneurological immaturity. Conclusion: We described a new TPO compound heterozygosity that severely impaired the TPO activity and membrane localization leading to severe CH and fetal goiter. This is the first report showing the neuropsychological evaluation in patients with dyshormonogenetic fetal goiter. More studies are needed to understand the neurodevelopmental outcomes of neonates with CH-induced fetal goiters.
Assuntos
Autoantígenos/genética , Hipotireoidismo Congênito/diagnóstico por imagem , Bócio/diagnóstico por imagem , Iodeto Peroxidase/genética , Proteínas de Ligação ao Ferro/genética , Mutação , Hipotireoidismo Congênito/genética , Análise Mutacional de DNA , Feminino , Bócio/genética , Humanos , Recém-Nascido , Masculino , Gravidez , Ultrassonografia Pré-NatalAssuntos
Bócio Nodular/complicações , Bócio Nodular/diagnóstico , Perda Auditiva Neurossensorial/complicações , Perda Auditiva Neurossensorial/diagnóstico , Glândula Tireoide/patologia , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/genética , Feminino , Bócio/diagnóstico , Bócio/genética , Bócio/patologia , Bócio Nodular/genética , Bócio Nodular/patologia , Perda Auditiva Neurossensorial/genética , Perda Auditiva Neurossensorial/patologia , Humanos , Hiperplasia/complicações , Hiperplasia/diagnóstico , Hiperplasia/genética , Mutação de Sentido Incorreto , Transportadores de Sulfato/genética , Adulto JovemRESUMO
BACKGROUND: Thyroid damage occurs during experimental iodine-deficient goiter and involution with iodine supplementation. This study investigated the dynamic microRNAs (miRNAs) expression profiles in iodine-deficient thyroids during adequate and excessive iodine supplementation. METHODS: Twenty-four female Wistar rats were randomly divided into control, low-iodine (LI), LI-1I, and LI-2I groups. The LI-1I and LI-2I groups were fed a LI diet for 12 weeks, followed by a onefold (adequate) or twofold (excessive) physiological dose of iodine for 4 weeks to induce involution. The miRNA expression profiles were evaluated and the potential functions of the differentially expressed miRNAs identified were explored. RESULTS: In the LI group, 20 miRNAs were downregulated and 8 were upregulated. After involution, 21 miRNAs recovered to the control group levels in the LI-1I group, which was more than the 17 that recovered in the LI-2I group. In addition, 8 new differentially expressed miRNAs were identified in the LI-1I group, which was less than the 13 found in the LI-2I group. Bioinformatics analyses indicated that all differentially expressed miRNAs were involved in different processes and pathways, such as autoimmune thyroid disease and the Ras signaling pathway. CONCLUSION: Differentially expressed miRNAs are involved in iodine-deficient goiter formation and involution. Supplementation with adequate, not excessive, iodine may be more beneficial to restore homeostasis.
Assuntos
Bócio , Iodo , MicroRNAs , Animais , Feminino , Bócio/induzido quimicamente , Bócio/genética , MicroRNAs/genética , Ratos , Ratos WistarRESUMO
Not required for Clinical Vignette.
Assuntos
Hipertireoidismo/metabolismo , Síndrome da Resistência aos Hormônios Tireóideos/metabolismo , Hormônios Tireóideos/metabolismo , Feminino , Bócio/genética , Humanos , Hipertireoidismo/genética , Masculino , Linhagem , Síndrome da Resistência aos Hormônios Tireóideos/genéticaRESUMO
Thyroid paragangliomas are distinctly rare primary thyroid neoplasms with nearly 75 cases reported worldwide. Due to their similar embryological origin and cytohistomorphology with other thyroid neoplasms, they may pose great diagnostic challenges for pathologists, radiologists, endocrinologists, as well as surgeons leading to unnecessary aggressive therapy. With recent advances in molecular genetics, the prognostic significance of such seemingly innocuous thyroid neoplasms has been better understood. In this manuscript, we describe such a case and present a systematic review of all reported cases till date giving an update on our current knowledge regarding their diagnostic pitfalls, pathology, and molecular genetics.
Assuntos
Paraganglioma/diagnóstico , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/diagnóstico , Tireoidectomia , Adulto , Biomarcadores Tumorais/genética , Biópsia por Agulha Fina , Diagnóstico Diferencial , Bócio/genética , Bócio/patologia , Humanos , Masculino , Paraganglioma/complicações , Paraganglioma/genética , Paraganglioma/cirurgia , Prognóstico , Glândula Tireoide/diagnóstico por imagem , Glândula Tireoide/cirurgia , Neoplasias da Glândula Tireoide/complicações , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/cirurgia , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Ultrassonografia DopplerRESUMO
BACKGROUND: Among patients with congenital hypothyroidism, 35% have dyshormonogenesis (DH) with thyroid gland in situ with or without goiter. The majority of DH cases are due to mutations in genes involved in thyroid hormone production as TG, TPO, SLC5A5/NIS, SLC26A4/PDS, IYD/DEHAL1, DUOX2, and DUOXA2, and are usually inherited on an autosomal recessive basis. Most previously reported cases of fetal hypothyroidism and goiter were related to TG or TPO mutations and recently DUOXA2. PATIENT: In a male patient with antenatal goiter treated with intraamniotic levothyroxine injections, whose long-term follow-up is described in detail, two novel NIS mutations were detected. Mutations of NIS were located in exon 1 (c.52G>A, p.G18R) and exon 13 (c.1546C>T, p.R516X), each mutation was inherited from parents, who are healthy carriers. The p.G18R mutation affecting the first transmembrane domain of the protein can be responsible for deficient iodide uptake. However, the second is a nonsense mutation leading probably to mRNA degradation. In addition, the patient has undergone a thyroidectomy and we have studied the thyroid tissue. The thyroid histology showed heterogeneity with large follicles, epithelial hyperplasia and many areas of fibrosis. Immunohistochemistry with NIS specific antibody showed NIS staining at the basolateral plasma membrane of the thyrocytes. CONCLUSIONS: We report the first case of fetal goitrous hypothyroidism due to two novel NIS mutations with access to thyroid tissue of the patient, specific histology studies and long-term follow-up. This case expands our knowledge and provides further insights on molecular causes of fetal goiter in humans.
Assuntos
Hipotireoidismo Congênito/genética , Bócio/genética , Mutação , Simportadores/genética , Adolescente , Criança , Pré-Escolar , Hipotireoidismo Congênito/tratamento farmacológico , Bócio/tratamento farmacológico , Humanos , Lactente , Recém-Nascido , Masculino , Diagnóstico Pré-Natal , Tiroxina/uso terapêutico , Resultado do Tratamento , Adulto JovemRESUMO
Thyroid stimulating hormone (TSH) is critical for normal development and metabolism. To better understand the genetic contribution to TSH levels, we conduct a GWAS meta-analysis at 22.4 million genetic markers in up to 119,715 individuals and identify 74 genome-wide significant loci for TSH, of which 28 are previously unreported. Functional experiments show that the thyroglobulin protein-altering variants P118L and G67S impact thyroglobulin secretion. Phenome-wide association analysis in the UK Biobank demonstrates the pleiotropic effects of TSH-associated variants and a polygenic score for higher TSH levels is associated with a reduced risk of thyroid cancer in the UK Biobank and three other independent studies. Two-sample Mendelian randomization using TSH index variants as instrumental variables suggests a protective effect of higher TSH levels (indicating lower thyroid function) on risk of thyroid cancer and goiter. Our findings highlight the pleiotropic effects of TSH-associated variants on thyroid function and growth of malignant and benign thyroid tumors.
Assuntos
Pleiotropia Genética , Estudo de Associação Genômica Ampla , Neoplasias da Glândula Tireoide/genética , Tireotropina/genética , Loci Gênicos , Predisposição Genética para Doença , Bócio/genética , Humanos , Análise da Randomização Mendeliana , Herança Multifatorial/genética , Mutação de Sentido Incorreto/genética , Fenótipo , Mapeamento Físico do Cromossomo , Prevalência , Fatores de Risco , Tireoglobulina/genética , Neoplasias da Glândula Tireoide/epidemiologiaRESUMO
Concomitant thyroid cancer in patients with congenital thyroid dyshormonogenesis (TD) is extremely rare and few cases of differentiated thyroid cancer in patients with TD have been reported thus far. In this study, we describe anaplastic thyroid cancer in a 46-year-old woman with TD who had two germline thyroglobulin (TG) gene mutation, c.3790T>C (p, Cys1264Arg) in exon 17 and a novel c.7070T>C (p.Leu2357Pro) in exon 41 of the TG gene. Two affected younger sisters were also found to have the same TG mutation but not anaplastic thyroid cancer. Any thyroid nodular lesions that develop in patients with TD should be investigated carefully.
Assuntos
Bócio/complicações , Bócio/genética , Mutação , Tireoglobulina/genética , Carcinoma Anaplásico da Tireoide/complicações , Carcinoma Anaplásico da Tireoide/genética , Neoplasias da Glândula Tireoide/complicações , Neoplasias da Glândula Tireoide/genética , Saúde da Família , Feminino , Mutação em Linhagem Germinativa , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , LinhagemRESUMO
PURPOSE: Mild thyroid peroxidase (TPO) deficiency is rare and can be extremely occult. This study aimed to replenish the phenotypic and genetic spectrum of mild TPO deficiency. METHODS: Four unrelated patients with progressive goiter were described in this study. Genes associated with congenital hypothyroidism were analyzed and in vitro functional experiments were conducted to evaluate the residual TPO enzyme activities of each mutant. RESULTS: The four patients (age: 5-27 years old) were characterized by progressive goiter, discordant alteration in thyroid hormones with free triiodothyronine (FT3) to free thyroxine (FT4) ratio ranging from 0.557 to 1.012, two with slightly elevated TSH level and two with normal TSH level. Six different mutations of TPO gene were identified including three novel mutations (p.Glu337Lys, p.Ala544Val, and p.Glu641Lysfs∗21). Two mutants (p.Asp224del and p.Ala544Val) with residual TPO activity of 41 and 65% may explain the mild TPO-deficient picture in our study. After levothyroxine (L-T4) therapy, three patients showed gradual decline of FT3 to FT4 ratio and two patients showed reduced thyroid size. CONCLUSION: Patients with mild TPO deficiency can present with progressive goiter, normal TSH level, and largely reserved TPO activities.