TSH Receptor Gene Research Articles

Case Reports of Familial Non-autoimmune Hyperthyroidism in Two Malaysian Families due to Germline-activating Mutations in the Thyrotropin Receptor Gene

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Mutation screening of the TSHR gene in 220 Chinese patients with congenital hypothyroidism

BackgroundDefects in the human thyroid stimulating hormone receptor (TSHR) gene are reported to be one of the causes of congenital hypothyroidism (CH). We aimed to identify mutations in Chinese patients with CH and analyze the relationships between TSHR phenotypes and clinical phenotypes. Methods220 patients with primary CH were screened for TSHR mutations by performing next-generation sequencing. All the exons and exon–intron boundaries of TSHR were analyzed. The function of 8 mutants in TSHR were further investigated in vitro. ResultsAmong 220 patients with CH, 15 distinct TSHR mutations were identified in 13 patients (5.91%, 13/220, including our previous reported 110 patients, carried with 10 mutations in 8 patients). We found five distinct mutations in the additional cohort of 110 CH patients and identified 7 mutations (including a novel mutation, p.S567R) were loss-of-function mutations. ConclusionOur study indicated that the prevalence of TSHR mutations was 5.91% among studied Chinese patients with CH. One novel TSHR variant was found and four genetic alterations revealed important role of the Ile216, Ala275, Asn372, Ser567 residues in signaling.

Bipolar limbic expression of auto-immune thyroid targets: thyroglobulin and thyroid-stimulating hormone receptor.

The associations between thyroid auto-immunity and neuro-psychiatric disorders are well-documented. However, there exists limited literature specifically linking auto-immune thyroid disease (AITD) to bipolar disorder (BD). Thus, we investigated the likely association between Hashimoto's disease and BD through the extra-thyroidal localisation of thyroid-stimulating hormone receptor (TSH-R) and thyroglobulin (TG) in limbic regions of normal and bipolar human adult brain. Further, we hypothesised that changes in thyroid expression in bipolar limbic cortex may contribute to mood dysregulation associated with BD. Immuno-chemistry and in-situ PCR were used to localise TSH-R/TG within the amygdala, cingulate gyrus and frontal cortex of normal (n = 5) and bipolar (n = 5) brains. Reverse-transcriptase qPCR provided fold-change differences in TSH-R gene expression. The results demonstrated reduced thyroid protein expression in bipolar limbic regions; these novel results correlate with other neuro-imaging reports that describe reduced cortico-limbic tissue volumes and neuro-physiological activity during BD. We also demonstrated TG-like proteins exclusive to bipolar amygdala neurons, and which relates to previous neuro-imaging studies of amygdala hyperactivity and enhanced emotional sensitivity in BD. Indeed, reduced TSH-R/TG in limbic regions may predispose to, or bear relevance in the pathophysiology of mood dysregulation and symptoms of BD. Further, we attribute mood dysregulation in BD to limbic-derived TSH-R, which probably provides potential targets for thyroid auto-immune factors during Hashimoto's disease. Consequently, this may lead to inactivated and/or damaged neurons. The neuro-pathology of diminished neuronal functioning or neuronal atrophy suggests a novel neuro-degeneration mechanism in BD.

Severe congenital hypothyroidia in homozygous mutation of the thyroid stimulating hormone receptor gene the thyroid peroxidase and tyroglobulin genes in Moroccan children

Severe congenital hypothyroidia in homozygous mutation of the thyroid stimulating hormone receptor gene the thyroid peroxidase and tyroglobulin genes in Moroccan children

MON-265 Congenital Hypothyroidism and Bilateral Ptosis Due to a Novel TSHR Gene Mutation

Background. Congenital hypothyroidism (CH) is most frequently caused by thyroid dysgenesis. Approximately 2% of cases with thyroid dysgenesis are familial. TSH receptor (TSHR) gene mutations have been reported in patients with thyroid gland dysgenesis; however, they are not known to be associated with extra-thyroidal anomalies. Clinical case. H.A presented to our clinic at 7 years of age with history of congenital hypothyroidism diagnosed at another institution and started on thyroxine during her first few days of life. Her newborn screen collected on DOL2 showed high TSH of 448 uIU/ml (nl., < 28.5 uIU/ml ) and low T4 of 2.3 ug/dl (nl., > 6.0 ). At age 7 years, her physical exam revealed the absence of a goiter and the presence of mild bilateral ptosis. One year later, a thyroid ultrasound was obtained and it demonstrated a small thyroid gland (right lobe,1.3x0.9x0.3 cm; left lobe, 1.1x1.0x0.2cm ). Her family history was significant for 2 out of her 5 siblings having a history of congenital hypothyroidism, mild ptosis and a small thyroid gland on thyroid ultrasound. Microarray analysis showed several regions of homozygosity including 14q24.2q31.3; of note, the TSHR gene is located in this chromosomal region. Targeted sequence analysis demonstrated a novel homozygous mutation in exon 9 of the TSHR gene (nucleotide change, c.847T>C), which resulted in amino acid change p.C283R. Conclusion. This is the first report of a patient with congenital hypothyroidism and bilateral ptosis due to a novel TSHR gene mutation. The mechanism underlying this association is unknown at this time. Targeted sequence analysis of TSHR gene of her parents as well as her siblings with the same phenotype will be pursued to confirm familial inheritance of this mutation.

Analysis of thyroid stimulating hormone receptor gene mutation in children with hyperthyroidism

Objective To explore the characterization of thyroid stimulating hormone receptor(TSHR) gene mutational spectrum in children with hyperthyroidism from Guangzhou. Methods Ninety children were diagnosed with hyperthyroidism from July 2009 to July 2014 in our institute. Their median age at diagnosis was(7.5±3.4) years, and there were 28 males and 62 females. Mutational analysis were performed by performing polymerase chain reaction(PCR) and DNA direct sequencing of exon 10 of TSHR gene. TSHR gene mutations from 50 unrelated healthy children were served as controls. The correlation between TSHR gene and hyperthyroidism in children was explored. Results A total of 3 mutations were identified in ninety children who were diagnosed with hyperthyroidism, one synonymous mutations(p.V614V), and two missense mutations(p.R707W and p. D727E). Mutation of p. V614V do not change amino acid and do not influence the structure and function of TSHR, no pathogenicity. p. R707W is a SNP associated with human cancers. The frequency of C allele of the D727E in children with hyperthyroidism was 86.7%, while 55.0% in the controls, significant different between the children with hyperthyroidism and the controls(P<0.01). In this study, a very high association between the D727E SNP and hyperthyroidism(OR=18.86, P<0.01) was found. Conclusion Three different mutations of TSHR gene exon 10 were identified in 90 children with hyperthyroidism, (c.1842A>G, p.V614V、c.2119C>T, p.R707W、c.2181G>C, p.D727E), there were association between p. D727E and hyperthyroidism, nor p. V614V and p. R707W. Finally, p. D727E may be correlated with hyperthyroidism in children. Key words: Hyperthyroidism; Children; Thyroid stimulating hormone receptor(TSHR); Gene; Mutation

Epidemiology of congenital hypothyroidism in France: recent data

Congenital hypothyroidism (CH) is the leading cause of preventable mental retardation. It is mainly due to thyroid dysgenesis or dyshormonogenesis with normally located gland, and detected at birth in developed countries, by mass biochemical screening of newborns. An increase in the incidence of congenital hypothyroidism with a normally located gland has been reported worldwide over the last three decades. The etiology of CH with a normally located gland remains elusive and the factors driving its clinical diversity are largely unknown. A role for known dyshormonogenesis-associated genetic variants or TSH receptor gene variants is well-known, but the possible effects of environmental agents toxic to the fetal and neonatal thyroid gland are currently being investigated.

Nonautoimmune congenital hyperthyroidism due to p.Asp633Glu mutation in the TSHR gene.

Most cases of congenital hyperthyroidism are autoimmune forms caused by maternal thyroid stimulating antibodies. Nonautoimmune forms of congenital hyperthyroidism caused by activating mutations of the thyrotropin receptor (TSHR) gene are rare. A woman gave birth to a boy during an emergency cesarean section at 33 weeks of gestation due to fetal tachycardia. On the 24th day of life, thyroid function tests were performed due to persistent tachycardia, and hyperthyroidism was confirmed. Auto-antibodies to TSHR, thyroid peroxidase, and thyroglobulin were not found. The patient was treated with propylthiouracil and propranolol, but hyperthyroidism was not well controlled. At 3 months of age, the patient had craniosynostosis and hydrocephalus, and underwent a ventriculoperitoneal shunt operation. Direct sequencing of the TSHR gene showed a heterozygous mutation of c.1899C>A (p.Asp633Glu) in exon 10. No mutations were discovered in any of the parents in a familial genetic study. We have reported a case of sporadic nonautoimmune congenital hyperthyroidism, by a missense mutation of the TSHR gene, for the first time in South Korea.

Central Tolerance Mechanisms to TSHR in Graves' Disease: Contributions to Understand the Genetic Association.

In the last 3 years, the association of thyrotropin receptor gene (TSHR) variations to Graves' disease (GD) has been confirmed. It is now well established that a 30 Kb region of intron 1 of the TSHR gene is linked to GD predisposition. Elucidating the mechanism(s) by which these polymorphisms confer susceptibility is difficult but would constitute an important advance in endocrine autoimmunity in general. Two hypotheses, both postulating TSHR gene regulatory mechanisms, are discussed. One postulates differential level of expression in the thymus, involving central tolerance. The other postulates a shift in TSHR differential splicing leading to the production of soluble proteins that will have easy access to antigen presenting cells, so it is focused in peripheral tolerance. A combination of the 2 hypothesis is feasible, especially under the light of recent evidence that have identified epigenetic factors acting on TSHR intron 1.

Clinical Significance of Thyroid-Stimulating Hormone Receptor Gene Mutations and/or Sodium-Iodine Symporter Gene Overexpression in Indeterminate Thyroid Fine Needle Biopsies.

Objectives: To examine the prevalence of genetic alterations of thyroid-stimulating hormone receptor (TSHR) gene and sodium-iodine symporter (NIS) in a series of thyroid fine needle biopsy (FNB) specimens with indeterminate cytology, and to assess the correlation of the type of genetic changes with clinical features and follow-up results in the target thyroid nodule.Methods: Between February 2015 and September 2017, 388 consecutive FNBs with indeterminate cytology were evaluated for TSHR mutations and NIS gene overexpression using ThyroSeqV.2 next-generation sequencing (NGS) panel. Medical records were reviewed for target nodules.Results: Among 388 indeterminate FNBs, TSHR mutations and/or NIS overexpression were detected in 25 (6.4%) nodules. Ten nodules (2.6%) harbored TSHR mutations only, 7 nodules (1.8%) over-expressed NIS gene only, and 8 nodules (2.1%) had both alterations. The TSHR mutations were located between codons 281 and 640, with codon 453 being the most frequently affected. The allelic frequency of the mutated TSHR ranged from 6 to 36%. One nodule with NIS overexpression was simultaneously detected EIF1AX mutation and GNAS mutation. Nodules with TSHR mutations and/or NIS overexpression presented hyperfunctioning (n = 4), hypofunctioning (n = 5), and isofunctioning (n = 3) on the available thyroid scintigraphies. Eight cases accompanied with hyperthyroidism in which only 1 was caused by the target nodule. Evidence of co-existing autoimmune thyroid disease (AITD) and multinodular goiter were found in 52% and 52% of cases, respectively. Seven nodules underwent surgeries and all were benign on final pathology. None of 9 nodules with follow-up by ultrasound (3~33 mon, median 12 mon) showed grow in size.Conclusions: TSHR mutations and/or NIS overexpression can be detected in pre-operative FNB specimens using the NGS approach. These genetic alterations occurred in 6.4% thyroid nodules in this consecutive series with indeterminate cytology. They present not only in hyperfunctioning nodules but also in hypo- or iso-functional nodules, indicating their prevalence may be higher than previously expected. Co-existing AITD was common in cases with these molecular alterations. None of our patients with TSHR mutations and/or NIS overexpression manifested malignant outcomes. How to use these two molecular markers in thyroid FNBs to guide our clinical practice warrants further investigation.

A case of congenital autonomous thyroid adenoma with a somatic activating gene mutation in the thyroid-stimulating hormone receptor

Abstract We report here a male case of autonomous adenoma (AA) in the thyroid that was caused by a somatic heterozygous mutation in the thyroid-stimulating hormone receptor (TSHR) gene at codon 453, which encodes the second transmembrane domain of the protein. This activating mutation of TSHR induced an increase in cell proliferation that resulted in the development of a thyroid goiter. The patient showed symptoms of hyperthyroidism since perinatal age and developed a thyroid goiter at the age of 1 year. Technetium scan showed a hot spot in the right lobe and weak tracer uptake in the left lobe of the thyroid, which were typical findings in AA. He underwent right hemi-thyroidectomy at 1 year and 10 months of age, and attained complete cure after surgery.

Analysis of chosen polymorphisms rs2476601 a/G – PTPN22, rs1990760 C/T – IFIH1, rs179247 a/G – TSHR in pathogenesis of autoimmune thyroid diseases in children

Background: Autoimmune thyroid diseases are multifactorial diseases with a genetic susceptibility and environmental factors. A potential role of the protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene, the interferon-induced helicase domain 1 (IFIH1) gene, the thyroid-stimulating hormone receptor (TSHR) gene polymorphisms on autoimmune thyroid diseases (AITDs) in adults has been established unequivocally, but there is still lack of research articles including group of children.Objective and hypotheses: To estimate the association of polymorphisms of PTPN22, IFIH1 and TSH-R genes with the pre-disposition to Graves’ disease (GD) and Hashimoto’s thyroiditis (HT) in children.Methods: The study was performed in 142 patients with GD, 57 with HT and 160 healthy volunteers. The three single-nucleotide polymorphisms (SNPs): rs2476601 – PTPN22, rs1990760 – IFIH1 and rs179247 – TSHR were genotyped by TaqMan SNP genotyping assay using the real-time PCR.Results: Rs2476601 A alleles were more frequent in patients with GD in comparison to healthy subjects (p = .009 with odds ratio [OR] = 2.13). Rs2476601 A alleles were more frequent in patients with HT in comparison to healthy subjects (p = .008, OR = 2.48). Rs1990760 T alleles were more frequent in male patients with GD in comparison to healthy males (p = .003, OR = 3.00). In case of HT patients, rs1990760 T alleles were also more frequent in males compared to healthy subjects (p = .086, OR =2.47). Rs179247 A alleles were more frequent in patients with GD in comparison to healthy subjects (p = 0.039, OR = 1.51).Conclusions: Rs2476601 A/G, Rs1990760 C/T and Rs179247 A/G polymorphisms could contribute to the development of AITDs in children. The main risk factor for rs2476601 and rs179247 is allele A. In case of rs1990760, the main risk factor is allele T.

Familial gestational hyperthyroidism caused by Val597ile mutant of TSH receptor gene with human chorionic gonadotropin hypersensitivity

Familial gestational hyperthyroidism caused by Val597ile mutant of TSH receptor gene with human chorionic gonadotropin hypersensitivity

Identification of Functional Thyroid Stimulating Hormone Receptor and TSHR Gene Mutations in Hepatocellular Carcinoma.

Extra-thyroid expression of thyroid stimulating hormone (TSH) receptor (TSHR) has been reported in normal liver tissues, but never assessed in hepatocellular carcinoma (HCC). Paired cancerous and non-cancerous HCC tissues were analyzed with TSHR expression assays. TSHR functional assessments and sequence analysis for the TSHR exon-10 were performed. TSHR overexpression was found in 150/197 (76.1%) HCCs. Higher TSHR expression was associated with unfavorable postoperative outcomes. Immunohistochemical analysis revealed predominantly nuclei/peri-nuclei localization of TSHR in cancerous tissues but cell membrane localization in non-cancerous parts. TSH stimulation on hepatoma cells resulted in increased cyclic adenosine monophosphate levels with altered cell sensitivity to cisplatin. Gene mutations leading to TSHR truncation were detected in 8/81 (9.9%) HCC tissues. Overexpression of TSHR was found in a great majority of HCC tissues and associated with unfavorable prognosis. Cell-based experiments and gene mutation analysis suggested that TSHR in HCCs was functional.

Thyroid Stimulating Hormone and Bone Mineral Density: Evidence From a Two-Sample Mendelian Randomization Study and a Candidate Gene Association Study.

With population aging, prevalence of low bone mineral density (BMD) and associated fracture risk are increased. To determine whether low circulating thyroid stimulating hormone (TSH) levels within the normal range are causally related to BMD, we conducted a two-sample Mendelian randomization (MR) study. Furthermore, we tested whether common genetic variants in the TSH receptor (TSHR) gene and genetic variants influencing expression of TSHR (expression quantitative trait loci [eQTLs]) are associated with BMD. For both analyses, we used summary-level data of genomewide association studies (GWASs) investigating BMD of the femoral neck (n = 32,735) and the lumbar spine (n = 28,498) in cohorts of European ancestry from the Genetic Factors of Osteoporosis (GEFOS) Consortium. For the MR study, we selected 20 genetic variants that were previously identified for circulating TSH levels in a GWAS meta-analysis (n = 26,420). All independent genetic instruments for TSH were combined in analyses for both femoral neck and lumbar spine BMD. In these studies, we found no evidence that a genetically determined 1-standard deviation (SD) decrease in circulating TSH concentration was associated with femoral neck BMD (0.003 SD decrease in BMD per SD decrease of TSH; 95% CI, -0.053 to 0.048; p = 0.92) or lumbar spine BMD (0.010 SD decrease in BMD per SD decrease of TSH; 95% CI, -0.069 to 0.049; p = 0.73). A total of 706 common genetic variants have been mapped to the TSHR locus and expression loci for TSHR. However, none of these genetic variants were associated with BMD at the femoral neck or lumbar spine. In conclusion, we found no evidence for a causal effect of circulating TSH on BMD, nor did we find any association between genetic variation at the TSHR locus or expression thereof and BMD. © 2018 The Authors. Journal of Bone and Mineral Research Published by WileyPeriodicals, Inc.

Cancer risk and clinicopathological characteristics of thyroid nodules harboring thyroid-stimulating hormone receptor gene mutations.

Thyroid-stimulating hormone receptor (TSHR) gene mutations play a critical role in thyroid cell proliferation and function. They are found in 20%-82% of hyperfunctioning nodules, hyperfunctioning follicular thyroid cancers (FTC), and papillary thyroid cancers (PTC). The diagnostic importance of TSHR mutation testing in fine needle aspiration (FNA) specimens remains unstudied. To examine the association of TSHR mutations with the functional status and surgical outcomes of thyroid nodules, we evaluated 703 consecutive thyroid FNA samples with indeterminate cytology for TSHR mutations using next-generation sequencing. Testing for EZH1 mutations was performed in selected cases. The molecular diagnostic testing was done as part of standard of care treatment, and did not require informed consent. TSHR mutations were detected in 31 (4.4%) nodules and were located in exons 281-640, with codon 486 being the most common. Allelic frequency ranged from 3% to 45%. Of 16 cases (12 benign, 3 FTC, 1 PTC) with surgical correlation, 15 had solitary TSHR mutations and 1 PTC had comutation with BRAF V600E. Hyperthyroidism was confirmed in all 3 FTC (2 overt, 1 subclinical). Of 5 nodules with solitary TSHR mutations detected at high allelic frequency, 3 (60%) were FTC. Those at low allelic frequency (3%-22%) were benign. EZH1 mutations were detected in 2 of 4 TSHR-mutant malignant nodules and neither of 2 benign nodules. We report that TSHR mutations occur in ∼5% thyroid nodules in a large consecutive series with indeterminate cytology. TSHR mutations may be associated with an increased cancer risk when present at high allelic frequency, even when the nodule is hyperfunctioning. Benign nodules were however most strongly correlated with TSHR mutations at low allelic frequency.

Identification of compound heterozygous TSHR mutations (R109Q and R450H) in a patient with nonclassic TSH resistance and functional characterization of the mutant receptors.

.Genetic defects of the TSH receptor (TSHR) signaling pathway cause a form of congenital hypothyroidism (CH) known as TSH resistance. Consistent with the physiological understanding that thyroidal iodine uptake is up-regulated by TSHR signaling, most patients with TSH resistance have low to normal thyroidal 123I uptake representing the classic TSH resistance. However, paradoxically high 123I uptake was reported in four molecularly-confirmed patients indicating nonclassic TSH resistance. Here, we report the fifth patient with the nonclassic phenotype. He was a 12-yr-old CH patient and treated with levothyroxine. At the age 11 yr, he showed slightly small thyroid gland and elevated thyroidal 123I uptake. Genetic analysis showed that he was compound heterozygous for two known missense mutations (Arg109Gln and Arg450His) in the TSHR gene. Further, the signal transduction of Arg109Gln-TSHR was defective in both Gs- and Gq-coupled pathways, while Arg450His-TSHR showed Gq-dominant defect. 123I uptake was evaluated earlier in 16 patients with TSH resistance, and a correlation between TSH levels and 123I uptake was shown in patients with specific genotypes (Arg450His or Leu653Val). Collectively, we have re-confirmed that the emergence of the nonclassic phenotype requires two factors: mutant TSHR with Gq-dominant coupling defect and relatively high levels of serum TSH.

Long-Term Follow-Up of a Patient with Sporadic Nonautoimmune Hyperthyroidism Due to a Thyrotropin-Receptor Mutation (D619G)

ABSTRACT Objective: Sporadic nonautoimmune hyperthyroidism caused by germline mutations of the thyrotropin receptor (TSHR) gene is a very rare disease that manifests as severe congenital hyperthyroidism. We describe a case presenting with sporadic nonautoimmune hyperthyroidism during adolescence. Methods: Laboratory data, imaging, histopathology, clinical follow-up, and DNA sequencing were evaluated. Results: The patient was born at term with a normal birth weight but showed increased growth velocity at approximately 7 months. He had no medical consultation before tachycardia was detected at a school physical examination at the age of 13 years. Thyroid function tests confirmed hyperthyroidism with negative anti-TSHR antibodies. After maintaining methimazole therapy for 12 years, he underwent total thyroidectomy, and the weight of the resected thyroid tissue was 131 g. The subsequent histopathologic findings showed an encapsulated follicular adenoma, adenomatous goiter, and hyperplastic changes of the foll...

Two Cases of Hypothyroidism with TSH Receptor Gene D727E Polymorphism that Converted to Hyperthyroidism after Many Years

Two Cases of Hypothyroidism with TSH Receptor Gene D727E Polymorphism that Converted to Hyperthyroidism after Many Years

Mild TSH resistance: Clinical and hormonal features in childhood and adulthood.

Mutations in TSH receptor (TSHR) are associated with TSH resistance, a genetic defect characterized by a heterogeneous phenotype ranging from severe hypothyroidism to subclinical hypothyroidism (SCH). We assessed the clinical and hormonal pattern of TSHR variants in a series of pediatric patients, and the long-term outcome of growth, biochemical measurements of metabolism, and neuropsychological functions in TSHR mutations carriers. Observational, retrospective study. Thirty four children (age 7days to 11years) and 18 adult carriers of TSHR variants. The TSHR gene was sequenced by PCR-amplified direct sequencing in 111 pediatric patients with slight to moderate elevation of TSH and normal FT4 levels. The study focused on the: auxological and biochemical parameters, thyroid ultrasound, bone age, bone mineral density (BMD), and intellectual outcome (IQ) were collected during the long follow-up (1-15years). Seventeen different TSHR variants (eight novel) were identified in 34 of the 111 pediatric patients, with a high prevalence of familial cases (27/34). Neonatal screening for congenital hypothyroidism was positive in half of the TSHR carriers. Growth, IQ, BMD, and biochemical parameters were normal in all subjects. Twenty patients received L-T4 replacement therapy, in all cases before genetic analysis. After re-evaluation, six patients resumed L-T4 therapy: they were compound heterozygous, or single heterozygous and with associated conditions at risk of thyroid impairment (SGA). No adults presented clinical features consistent with impaired thyroid function. Children carriers of TSHR variants, regardless of L-T4 treatment, show regular growth and neuropsychological development, with no evident biochemical and US alterations.