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Context: T4-binding globulin (TBG), a protein secreted by the liver, is the main thyroid hormone (TH) transporter in human serum. TBG deficiency is characterized by reduced serum TH levels, but normal free TH and TSH and absent clinical manifestations. The inherited form of TBG deficiency is usually due to a mutation in the TBG gene located on the X-chromosome., Objective: Among the 75 families with X-chromosome-linked TBG deficiency identified in our laboratory, no mutations in the TBG gene were found in four families. The aim of the study was to identify the mechanism of TBG deficiency in these four families using biochemical and genetic studies., Design: Observational cohort, prospective., Setting: University research center., Patients: Four families with inherited TBG deficiency and no mutations in the TBG gene., Intervention: Clinical evaluation, thyroid function tests, and targeted resequencing of 1 Mb of the X-chromosome., Results: Next-generation sequencing identified a novel G to A variant 20 kb downstream of the TBG gene in all four families. In silico analysis predicted that the variant resides within a liver-specific enhancer. In vitro studies confirmed the enhancer activity of a 2.2-kb fragment of genomic DNA containing the novel variant and showed that the mutation reduces the activity of this enhancer. The affected subjects share a haplotype of 8 Mb surrounding the mutation, and the most recent common ancestor among the four families was estimated to be 19.5 generations ago (95% confidence intervals, 10.4-37)., Conclusions: To our knowledge, the present study is the first report of an inherited endocrine disorder caused by a mutation in an enhancer region.

Aim: The aim of this study was to determine the prevalence of autoimmune thyroid disease in Turner syndrome (TS) and the association between thyroid autoantibodies (TAA), thyroid dysfunction, age, and karyotype., Methods: Sixty-nine girls with TS were divided into two groups according to being TAA-positive or TAA-negative. TAA and thyroid hormone concentrations were determined by immunochemiluminescence., Results: One third (23/69) of the girls were TAA positive, with antibody prevalence increasing with age. Of the TAA-positive girls, seven were hypothyroid and three hyperthyroid. Compared with the TAA-negative group, the girls in the TAA-positive group were significantly older (p<0.05). For those who were TAA positive, 26.3% of patients were 5-10 years old, 37.1% 10-15 years old, and 62.5% above the age of 15 years., Conclusion: Chinese girls with TS are prone to Hashimoto's thyroiditis, especially those older than 5 years, and routine thyroid testing is advocated thereafter on a yearly basis. There was no specific association between the incidence of autoimmune thyroid disease and TS karyotypes.

Background: A potential role of preproghrelin polymorphisms on autoimmune thyroid diseases (AITDs) has not been established equivocally yet., Aim: To estimate the association of two polymorphisms of preproghrelin gene with the predisposition to Graves' disease (GD) and Hashimoto's thyroiditis (HT) in children., Methods: The study was performed in 145 patients with GD, 87 with HT and 161 healthy volunteers. The two single nucleotide polymorphisms (SNPs) rs696217 (C&#95;3151003&#95;20) and rs4684677 (C&#95;25607748&#95;10) in the preproghrelin gene were genotyped by TaqMan SNP genotyping assay using the real-time PCR., Results: Rs4684677 T alleles were more frequent in HT patients (99% in women and 100% in men) in comparison to healthy subjects (p = 0.002) with OR = 8.0 and 95% confidence interval for OR: 1.8-206.7. In women group, rs4684677 T alleles were more frequent compared to healthy controls (99%) in HT (p = 0.02) with OR = 6.7 and 95% confidence interval for OR: 1.2-168.37. Frequency of the SNP rs696217 did not differ between the groups. There was a significant relationship between rs696217 polymorphisms and anti-TSHR antibodies level (p = 0.036) in women from GD/HT groups. A significant relationship between rs696217 polymorphisms and anti-TG antibodies level in GD women group (p = 0.038) and between rs696217 polymorphisms and fT4 concentration (p = 0.03) were found., Conclusions: Rs4684677 T/A polymorphisms in preproghrelin gene could contribute to development of AITDs in children and T allele is the main risk factor.

Symptoms of a newly discovered X-chromosomal severe mental retardation disease were published by William Allan, Nash Herndon and Florence Dudley in 1944. Patients suffered from muscle weakness and a developmental delay not able to sit, walk and speak. In addition, they showed an endocrinological phenotype with abnormal thyroid hormone constellations. The reason for the Allan-Herndon-Dudley syndrome was found in a mutation of the monocarboxylate transporter 8 (MCT8, SLC16A2), a specific thyroid hormone transporter.

Thyroid stimulating hormone (TSH) hormone levels are normally tightly regulated within an individual; thus, relatively small variations may indicate thyroid disease. Genome-wide association studies (GWAS) have identified variants in PDE8B and FOXE1 that are associated with TSH levels. However, prior studies lacked racial/ethnic diversity, limiting the generalization of these findings to individuals of non-European ethnicities. The Electronic Medical Records and Genomics (eMERGE) Network is a collaboration across institutions with biobanks linked to electronic medical records (EMRs). The eMERGE Network uses EMR-derived phenotypes to perform GWAS in diverse populations for a variety of phenotypes. In this report, we identified serum TSH levels from 4,501 European American and 351 African American euthyroid individuals in the eMERGE Network with existing GWAS data. Tests of association were performed using linear regression and adjusted for age, sex, body mass index (BMI), and principal components, assuming an additive genetic model. Our results replicate the known association of PDE8B with serum TSH levels in European Americans (rs2046045 p = 1.85×10-17, β = 0.09). FOXE1 variants, associated with hypothyroidism, were not genome-wide significant (rs10759944: p = 1.08×10-6, β = -0.05). No SNPs reached genome-wide significance in African Americans. However, multiple known associations with TSH levels in European ancestry were nominally significant in African Americans, including PDE8B (rs2046045 p = 0.03, β = -0.09), VEGFA (rs11755845 p = 0.01, β = -0.13), and NFIA (rs334699 p = 1.50×10-3, β = -0.17). We found little evidence that SNPs previously associated with other thyroid-related disorders were associated with serum TSH levels in this study. These results support the previously reported association between PDE8B and serum TSH levels in European Americans and emphasize the need for additional genetic studies in more diverse populations.

Autoimmune thyroid disease (AITD), known as the most common organ-specific autoimmune disorder, is frequently accompanied by other organ and non-organ-specific autoimmune diseases, including rheumatoid arthritis (RA). Although the exact pathogenic mechanisms of the coexistence of autoimmune disorders are still not completely defined, genetics, immune defects, hormones and environmental factors may play key roles in polyautoimmunity. In this review, the prevalence of AITD and antithyroid autoantibodies in RA patients and rheumatic manifestations in association with thyroid autoimmunity are discussed. Finally, we review the role of genetics in the association of both AITD and RA, especially CTLA-4 and PTPN22 polymorphisms.

Objectives: To describe the specificities and complications of thyroid surgery in children and adolescents., Material and Methods: This retrospective study was based on 64 patients under the age of 18 who underwent thyroid surgery between January 2004 and March 2012, with two operations in one case. The following data were analysed: anatomical variants of the recurrent laryngeal nerve, postoperative recurrent laryngeal nerve paralysis rate, postoperative hypoparathyroidism rate, and histological results., Results: Two cases of right non-recurrent inferior laryngeal nerve were observed (2.2% of the 93 recurrent laryngeal nerves dissected). One case of persistent left recurrent laryngeal nerve paralysis was observed (1.1%) despite intraoperative recurrent laryngeal nerve monitoring. Eight cases of immediate postoperative hypocalcaemia were observed (23.5% of the 34 total thyroidectomies) and permanent hypocalcaemia was observed in 5 cases (14.7%) with a significantly lower immediate postoperative serum calcium than in the case of transient hypocalcaemia (P=0.035). Among the 11 patients operated for familial medullary thyroid carcinoma (MTC), 36.3% presented one or more sites of C-cell carcinoma. Among the 32 patients operated for thyroid nodule, 6.3% presented papillary adenocarcinoma. Histological results were benign in all other cases., Conclusions: Thyroid surgery in children and adolescents is part of global multidisciplinary management of thyroid disorders in children. Recurrent laryngeal nerve paralysis is a rare complication, but may occur despite the use of intraoperative recurrent laryngeal nerve monitoring. Permanent hypoparathyroidism is the most common complication and is correlated with immediate postoperative serum calcium. Systematic prophylactic total thyroidectomy in patients with a RET proto-oncogene mutation allowed early diagnosis of MTC in one-third of cases. In view of the low rate of malignant nodules in our series, the malignant thyroid nodule rates reported in children in the literature may be overestimated., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

Neurofibromatosis type 1 (NF1) is a well-known genetic disorder characterized by café-au-lait spots and neurofibromas, but many other clinical characteristics and associated comorbidities also have been reported. This study aimed to characterize NF1 further by investigating its association with anthropometric characteristics and other diseases. We performed a case-control study of 227 NF1 patients (101 male, 126 female) and a randomly selected age- and sex-matched control group of 681 non-NF1 patients (303 male, 378 female) who visited our institution in Japan. We examined adult (≥20 years) height and body mass index (BMI), and, in the total sample, allergic diseases (bronchial asthma [BA], atopic dermatitis [AD] and allergic rhinitis) and other respiratory cardiovascular and psychiatric disorders. In adults, the mean BMI was lower in the NF1 group than in the control group, and was significantly statistically different among men (P = 0.0238). In the whole sample, the prevalences of BA (P = 0.0184), AD (P = 0.0144) and valvular heart disease (P = 0.0166) were significantly greater in the NF1 group than in the control group. To date, no similar research on the BMI or the prevalence of allergic disease in NF1 patients has been reported. Our results suggest that NF1 patients tend to have lower BMI and may have alterations in specific metabolic pathways and altered allergic immunity., (© 2014 Japanese Dermatological Association.)

Thyroid hormone action is predominantly mediated by thyroid hormone receptors (THRs), which are encoded by the thyroid hormone receptor α (THRA) and thyroid hormone receptor β (THRB) genes. Patients with mutations in THRB present with resistance to thyroid hormone β (RTHβ), which is a disorder characterized by elevated levels of thyroid hormone, normal or elevated levels of TSH and goitre. Mechanistic insights about the contributions of THRβ to various processes, including colour vision, development of the cochlea and the cerebellum, and normal functioning of the adult liver and heart, have been obtained by either introducing human THRB mutations into mice or by deletion of the mouse Thrb gene. The introduction of the same mutations that mimic human THRβ alterations into the mouse Thra and Thrb genes resulted in distinct phenotypes, which suggests that THRA and THRB might have non-overlapping functions in human physiology. These studies also suggested that THRA mutations might not be lethal. Seven patients with mutations in THRα have since been described. These patients have RTHα and presented with major abnormalities in growth and gastrointestinal function. The hypothalamic-pituitary-thyroid axis in these individuals is minimally affected, which suggests that the central T3 feedback loop is not impaired in patients with RTHα, in stark contrast to patients with RTHβ.

Normal thyroid metabolism is essential for human development, including the formation and functioning of the central and peripheral nervous system. Disorders of thyroid metabolism are increasingly recognized within the spectrum of paediatric neurological disorders. Both hypothyroid and hyperthyroid disease states (resulting from genetic and acquired aetiologies) can lead to characteristic neurological syndromes, with cognitive delay, extrapyramidal movement disorders, neuropsychiatric symptoms, and neuromuscular manifestations. In this review, the neurological manifestations of genetic disorders of thyroid metabolism are outlined, with particular focus on Allan-Herndon-Dudley syndrome and benign hereditary chorea. We report in detail the clinical features, major neurological and neuropsychiatric manifestations, molecular genetic findings, disease mechanisms, and therapeutic strategies for these emerging genetic 'brain-thyroid' disorders., (© 2014 The Authors. Developmental Medicine & Child Neurology published by John Wiley & Sons Ltd on behalf of Mac Keith Press.)

The analysis of polymorphisms of genes CYP1A1 (2454A > G,-3798T> C); CYP1A2 (-163C > A,-2467delT); TPO (2173A > C, 769G > T); DIO2 (274A > G) in women from the oil organic synthesis plant and the control group with thyroid disease (autoimmune thyroiditis and nodular goiter) has been performed. Molecular genetic markers of predisposition to the development of thyroid disease are: GG genotype and allele G gene DIO2 (274A > G), CT and CC genotypes of the gene CYP1A1 (-3798T > C), associated with the development of nodular goiter, and DD genotypes TD CYP1A2 gene (-2467delT), associated with the development of autoimmune thyroiditis. There was shown an association of polymorphic variants of the gene DIO2 (274A > G) with elevated levels of antibodies to TPO and TPO gene (2173A > C) with elevated levels of free T4.

Background: Fine-needle aspiration (FNA) aids in the diagnosis of thyroid nodules. The expression of previously implicated genes was examined to potentially discriminate between benign and malignant thyroid samples., Methods: Patients included for study had cytology demonstrating follicular cells of undetermined significance, atypical cells of undetermined significance, follicular neoplasm, or suspicion of malignancy with one of the following postoperative diagnoses: follicular thyroid adenomas, follicular thyroid carcinomas, or follicular variant of papillary thyroid carcinomas (FV-PTCs). FNA and tumor expression of human telomerase reverse transcriptase (hTERT), high-mobility group A2 (HMGA2), and trefoil factor 3/3-galactoside-binding lectin (T/G ratio) were analyzed., Results: T/G ratios were not significantly different in the malignant and benign groups. HMGA2 was overexpressed in carcinoma states; however, only FV-PTCs were significant (P = .006). Tumor hTERT expression was detected in 25% of follicular thyroid carcinomas, whereas 5% of FV-PTCs and 10% of follicular thyroid adenomas had expression. FNA aspirates showed similar results., Conclusions: Although HMGA2 and hTERT showed differential expression, they did not consistently differentiate benign from malignant. Further study based on global gene expression is needed to identify markers that could serve as a diagnostic tool., (Copyright © 2014 Elsevier Inc. All rights reserved.)

To investigate the association of CLEC16A gene polymorphisms and autoimmune thyroid diseases (AITDs). Six hundred sixty seven Han Chinese patients with AITDs were selected as study subjects, including 417 patients with Graves' disease (GD), 250 patients with Hashimoto's thyroiditis (HT) and 301 healthy control patients. Polymerase chain reaction-restriction fragment length polymorphism (RFLP) and the mass spectrometry technique were used to genotype five CLEC16A single-nucleotide polymorphisms (SNPs) (rs12708716, rs12917716, rs12931878, rs2903692, and rs6498169). Higher frequency of G allele of rs6498169 CLEC16A gene in AITDs patients [P = 0.029, odds ratio (OR) 1.29 and 95% confidence interval 1.022-1.505] was observed. In addition an association between rs6498169 and HT was observed with statistical significance (P = 0.018, OR 1.335, 95% confidence interval 1.051-1.696). Furthermore, the GG haplotype containing the major allele of (rs12708716 and rs6498169) was associated with an increased risk of HT (P = 0.0148, OR 1.344). When patients with HT and controls were compared, results from the dominant and recessive models showed that the genotype frequency of rs6498169 were at borderline levels (P = 0.054 and P = 0.05), and the other four SNPs of CLEC16A gene showed no significant association with AITDs. Our results suggest that polymorphisms rs6498169 of CLEC16A gene confers susceptibility to AITDs. We therefore disclose for the first time the association of rs6498169 SNP with AITDs., (Copyright © 2014 Muhali et al.)

Autoimmune thyroid disease (AITD) is a multifactorial disease in which autoimmunity against thyroid antigens develops against a particular genetic background facilitated by exposure to environmental factors. Immunogenicity of the major thyroid antigens thyroid peroxidase, thyroglobulin (TG) and thyrotropin receptor (TSHR) is increased by genetic polymorphisms, a high number of antigenic peptides available for binding to human leukocyte antigen (HLA), and a high degree of glycosylation. Antigens bound to HLA are presented by antigen-presenting cells to T cell receptors. Further interaction between both cells is required via binding of CD40 ligand to CD40 and of B7-1/2 to CD28 for activation of T cells. Complex regulatory mechanisms serve to prevent an immune response directed against 'self'-antigens in the thymus (central tolerance) and in peripheral tissues (peripheral tolerance) with the help of regulatory T cells. Breakdown of tolerance to thyroid antigens can result in thyroid autoimmunity, which may happen in subjects who have the wrong genes and who are exposed to the wrong environment. Polymorphisms in thyroid genes (TG, TSHR) and immunoregulatory genes (HLA, CTLA4, PTPN22, CD40, FCRL3, IL2RA, FOXP3) would contribute for about 70% to AITD, and environmental exposures (like iodine, smoking, infections, parity) for the remaining 30%. Thyroid-infiltrating activated T cells may lead to cell-mediated immunity, thyroid injury and eventually hypothyroidism, whereas humoral immunity via TSHR-stimulating antibodies may give rise to hyperthyroidism. Pediatric Hashimoto's and Graves' disease are less prevalent than in adults, and the female preponderance is also less marked in children. The discrepancy is probably due to relatively less involvement of environmental insults in children, whereas the prevalence of risk alleles in AITD children is higher than in AITD adults.

Histone deacetylases (HDACs) have been associated with human malignant tumor development and progression, and HDAC inhibitors are currently being explored as anticancer agents in clinical trials. The present study aimed to evaluate the clinical significance of HDAC-1, HDAC-2, HDAC-4, and HDAC-6 proteins' expression in human malignant and benign thyroid lesions. HDAC-1, HDAC-2, HDAC-4, and HDAC-6 proteins' expression was assessed immunohistochemically on paraffin-embedded thyroid tissues obtained from 74 patients with benign and malignant thyroid lesions. Enhanced HDAC-2 and HDAC-6 expression was significantly more frequently observed in malignant, compared to benign, thyroid lesions (p = 0.0042 and p = 0.0069, respectively). Enhanced HDAC-2, HDAC-4, and HDAC-6 expression was significantly more frequently observed in cases with papillary carcinoma compared to hyperplastic nodules (p = 0.0065, p = 0.0394, and p = 0.0061, respectively). In malignant thyroid lesions, HDAC-1, HDAC-4, and HDAC-6 expression was significantly associated with tumor size (p = 0.0169, p = 0.0056, and p = 0.0234, respectively); HDAC-2 expression with lymphatic and vascular invasion (p = 0.0299 and p = 0.0391, respectively); and HDAC-4 expression with capsular invasion (p = 0.0464). The cellular pattern of HDAC-1 and HDAC-2 distribution (nuclear vs. nuclear and cytoplasmic) presented a distinct discrimination between malignant and benign thyroid lesions (p = 0.0030 and p = 0.0028, respectively) as well as between papillary carcinoma and hyperplastic nodules (p = 0.0036 and p = 0.0028, respectively). HDAC-1, HDAC-2, HDAC-4, and HDAC-6 may be associated with the malignant thyroid transformation and could be considered as useful biomarkers and possible therapeutic targets in this neoplasia.

Recent advances in our understanding of genetic-epigenetic interactions have unraveled new mechanisms underlying the etiology of complex autoimmune diseases. Autoimmune thyroid diseases (AITDs) are highly prevalent, affecting 1% to 5% of the population. The major AITDs include Graves disease (GD) and Hashimoto's thyroiditis (HT); although these diseases contrast clinically, their pathogenesis involves shared immunogenetic mechanisms. Genetic data point to the involvement of both shared and unique genes. Among the shared susceptibility genes, HLA-DRβ1-Arg74 (human leukocyte antigen DR containing an arginine at position β74) confers the strongest risk. Recent genome-wide analyses have revealed new putative candidate genes. Epigenetic modulation is emerging as a major mechanism by which environmental factors interact with AITD susceptibility genes. Dissecting the genetic-epigenetic interactions underlying the pathogenesis of AITD is essential to uncover new therapeutic targets.

Background: Resistance to thyroid hormone (RTH) is a rare condition usually diagnosed in patients with classic thyroid function tests (TFTs) of elevated thyroid hormone levels with nonsuppressed TSH. The presence of autoimmune thyroid disease (AITD) can confound the clinical diagnosis of RTH. A family was evaluated because several members had elevated TSH and normal or low serum T4 concentrations with AITD. While these individuals were initially reported to have RTH, they were found to have a normal thyroid hormone receptor beta (THRB) gene sequence, and three other asymptomatic family members were found to harbor the variant TRβ G339S., Methods: The THRB gene was sequenced in 19 members of a large Mexican/Aztec family. In vitro expression of the mutant TRβ protein was performed, as well as computer modeling of the variant compared to known mutations in the flanking codons., Results: Investigation of an individual with AITD who was incorrectly diagnosed with RTH led to the fortuitous discovery of a THRB gene variant (G339S) in the proposita's father, paternal aunt, and cousin. This variant was not detected in analysis of 124 unrelated alleles. All individuals harboring G339S had normal TFTs. Normal in vitro expression and function of G339S and molecular modeling predicted that this variant would not have an effect on the hypothalamic-pituitary-thyroid axis as determined by thyroid hormone binding in vitro and thyroid function tests in vivo, despite profound effects seen in mutations in the adjacent codons 338 and 340., Conclusion: We report an individual with normal TFTs and AITD harboring a novel THRB gene variant. In addition to illustrating the importance of accurate diagnosis of thyroid disease so that proper treatment and counseling can be given, TRβ codon 339 is not essential for normal TRβ function.

The TSH receptor (TSHR) is a member of the glycoprotein hormone receptors, a subfamily of family A G protein-coupled receptors. The TSHR is of great importance for the growth and function of the thyroid gland. The TSHR and its endogenous ligand TSH are pivotal proteins with respect to a variety of physiological functions and malfunctions. The molecular events of TSHR regulation can be summarized as a process of signal transduction, including signal reception, conversion, and amplification. The steps during signal transduction from the extra- to the intracellular sites of the cell are not yet comprehensively understood. However, essential new insights have been achieved in recent years on the interrelated mechanisms at the extracellular region, the transmembrane domain, and intracellular components. This review contains a critical summary of available knowledge of the molecular mechanisms of signal transduction at the TSHR, for example, the key amino acids involved in hormone binding or in the structural conformational changes that lead to G protein activation or signaling regulation. Aspects of TSHR oligomerization, signaling promiscuity, signaling selectivity, phenotypes of genetic variations, and potential extrathyroidal receptor activity are also considered, because these are relevant to an understanding of the overall function of the TSHR, including physiological, pathophysiological, and pharmacological perspectives. Directions for future research are discussed.

The important physiological actions of the thyroid hormones are mediated by binding to nuclear thyroid hormone receptors (TRs), encoded by two genes TRalpha and TRbeta. These receptors act as hormone-dependent transcription factors by binding to DNA motifs located in the regulatory regions of target genes and recruiting coregulators (coactivators and corepresors), which alter chromatin structure. Novel thyromimetics have been developed that bind preferentially TRbeta could be used for treatment of hyperlipidemia and obesity. TRbeta gene mutations cause resistance to thyroid hormones (RTH), characterized by inappropriately high thyroid-stimulating hormone (TSH) levels due to lack of feedback inhibition of thyroid hormones on the hypothalamus and pituitary gland, and to reduced sensitivity of other TRbeta target tissues to thyroid hormones. Very recently, patients heterozygous for TRalpha mutations have been identified. These patients exhibit clinical symptoms of hypothyroidism in TRalpha target tissues such as intestine or hearth and near normal circulating TSH and thyroid hormone levels.

Fine-needle aspiration cytology (FNC) is the primary means to distinguish benign form malignant nodules. Aim of this study is to evaluate the diagnostic value of BRAF(V600E) and RET/PTC oncogenes in a large cohort of thyroid nodules with inconclusive FNC. We searched for BRAF(V600E) and RET/PTC in 299 thyroid nodule aspirates then removed by surgery. RET/PTC demonstrated a poor specificity. The search for BRAF(V600E) demonstrated to be useful in 25 cases, identifying a PTC in 2 false negative, 2 inadequate, 11 indeterminate and 10 suspicious FNC. Detection of BRAF(V600E) revealed to be a useful tool to refine inconclusive cytology.

Orbital fibroblast differentiation to adipocytes is a peroxisome proliferator-activated receptor g (PPARg)-dependent process essential for pathogenic tissue remodeling in Graves' orbitopathy (GO). PPARg2 Pro¹²Ala polymorphism modulates expression and/or function of the molecule encoded by this gene and is a promising locus of GO. Here, we analyzed associations of PPARg2 Pro¹²Ala with clinical manifestation of GO in 742 Polish Caucasians including 276 Graves' disease (GD) patients. In our study, the Ala¹² allele and Ala¹² variant (Ala¹²Ala and/or Pro¹²Ala genotype) decreased the risk of GO (p = 0.000012 and p = 0.00013). Moreover, Ala¹²Ala genotype was observed only in patients without GO (p = 0.002). GD patients with Ala¹² variant had less active and less severe eye symptoms. Female carriers of the Ala¹² allele rarely developed GO, but the marker was not related to symptoms of GO. The opposite finding was recorded in males, in whom the studied polymorphism was related to activity, but not to the development, of GO. In Ala¹² variant carriers without familial history of thyroid disease, risk of GO was lower than in persons with a familial background. The Ala¹² allele seemed to protect smokers from GO, but in nonsmokers, such a relation was not obvious. A multivariate analysis indicated the Pro¹²Ala marker as an independent risk factor of eye symptoms (p = 0.0001) and lack of Ala increases the risk of GO 3.24-fold. In conclusion, the gain-of-function Ala¹² variant protects against GO and modulates the course of the disease.

Background: Elevations or deficits in thyroid hormone levels are responsible for a wide range of neonatal and adult phenotypes. Several genome-wide, candidate gene, and meta-analysis studies have examined thyroid hormones in adults; however, to our knowledge, no genetic association studies have been performed with neonatal thyroid levels., Methods: A population of Iowa neonates, term (n = 827) and preterm (n = 815), were genotyped for 45 single-nucleotide polymorphisms (SNPs). Thyroid-stimulating hormone (TSH) values were obtained from the Iowa Neonatal Metabolic Screening Program. ANOVA was performed to identify genetic associations with TSH concentrations., Results: The strongest association was rs4704397 in the PDE8B gene (P = 1.3 × 10(-4)), followed by rs965513 (P = 6.4 × 10(-4)) on chromosome 9 upstream of the FOXE1 gene. Both of these SNPs met statistical significance after correction for multiple testing. Six other SNPs were marginally significant (P < 0.05)., Conclusion: We demonstrated for the first time two genetic associations with neonatal TSH levels that replicate findings with adult TSH levels. These SNPs should be considered early predictors of risk for adult diseases and conditions associated with thyroid hormone levels. Furthermore, this study provides a better understanding of the thyroid profile and potential risk for thyroid disorders in newborns.

Environmental and genetic factors are thought to be involved in the pathogenesis of autoimmune thyroid diseases (AITD), which include Graves' disease, Hashimoto's thyroiditis. Polymorphisms of vitamin D receptor (VDR) were implicated in AITDs risk. To date, many studies have evaluated the association between a functional polymorphism in the VDR gene and AITDs risk; however, the result is still ambiguous and inconclusive. To address the association of VDR gene FokI (rs10735810), TaqI (rs731236), BsmI (rs1544410), and ApaI (rs7975232) polymorphisms with AITD risk by meta-analysis. By searching the relevant literature, a total of eight studies were identified and meta-analyzed. HWE for each study are checked. Crude odds ratios (OR) with 95 % confidence intervals (CIs) were used to assess the strength of association in the allele polymorphism, codominant model, dominant model, and recessive model. The result indicates that the BsmI or TaqI polymorphisms is significantly associated with AITD risk (OR = 0.801 95 % CI 0.705, 0.910, Pz = 0.001 for B vs. b; OR = 0.854, 95 % CI 0.757, 0.963, Pz = 0.010 for t vs. T), while the ApaI or FokI polymorphism do not. In the subgroup analysis in Europeans, the decreased risk of AITD remained for the B or t variant. This gene-based analysis indicates that, based on current evidence from published studies, the cumulative effect of BsmI or TaqI polymorphisms in VDR is significantly associated with AITD.

Diabetes mellitus (DM) disrupts the pituitary-thyroid axis and leads to a higher prevalence of thyroid disease. However, the role of reactive oxygen species in DM thyroid disease pathogenesis is unknown. Dual oxidases (DUOX) is responsible for H(2)O(2) production, which is a cosubstrate for thyroperoxidase, but the accumulation of H(2)O(2) also causes cellular deleterious effects. Nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) is another member of the nicotinamide adenine dinucleotide phosphate oxidase family expressed in the thyroid. Therefore, we aimed to evaluate the thyroid DUOX activity and expression in DM rats in addition to NOX4 expression. In the thyroids of the DM rats, we found increased H(2)O(2) generation due to higher DUOX protein content and DUOX1, DUOX2, and NOX4 mRNA expressions. In rat thyroid PCCL3 cells, both TSH and insulin decreased DUOX activity and DUOX1 mRNA levels, an effect partially reversed by protein kinase A inhibition. Most antioxidant enzymes remained unchanged or decreased in the thyroid of DM rats, whereas only glutathione peroxidase 3 was increased. DUOX1 and NOX4 expression and H(2)O(2) production were significantly higher in cells cultivated with high glucose, which was reversed by protein kinase C inhibition. We conclude that thyroid reactive oxygen species is elevated in experimental rat DM, which is a consequence of low-serum TSH and insulin but is also related to hyperglycemia per se.

Context: Genetic factors play a major role in the etiology of autoimmune thyroid disease (AITD) including Graves' disease (GD) and Hashimoto's thyroiditis (HT). We have previously identified three loci on chromosomes 10q, 12q, and 14q that showed strong linkage with AITD, HT, and GD, respectively., Objectives: The objective of the study was to identify the AITD susceptibility genes at the 10q, 12q, and 14q loci., Design and Participants: Three hundred forty North American Caucasian AITD patients and 183 healthy controls were studied. The 10q, 12q, and 14q loci were fine mapped by genotyping densely spaced single-nucleotide polymorphisms (SNPs) using the Illumina GoldenGate genotyping platform. Case control association analyses were performed using the UNPHASED computer package. Associated SNPs were reanalyzed in a replication set consisting of 238 AITD patients and 276 controls., Results: Fine mapping of the AITD locus, 10q, showed replicated association of the AITD phenotype (both GD and HT) with SNP rs6479778. This SNP was located within the ARID5B gene recently reported to be associated with rheumatoid arthritis and GD in Japanese. Fine mapping of the GD locus, 14q, revealed replicated association of the GD phenotype with two markers, rs12147587 and rs2284720, located within the NRXN3 and TSHR genes, respectively., Conclusions: Fine mapping of three linked loci identified novel susceptibility genes for AITD. The discoveries of new AITD susceptibility genes will engender a new understanding of AITD etiology.

Mutations in the RET proto-oncogene have been implicated in the pathogenesis of several forms of medullary thyroid cancer (MTC). Multiple endocrine neoplasia type 2 (MEN-2) is an autosomal dominant syndrome caused by germline activating mutations of the RET proto-oncogene and has been categorized into three distinct clinical forms. MEN-2A is associated with MTC, bilateral pheochromocytoma, and primary hyperparathyroidism. MEN-2B is associated with MTC, bilateral pheochromocytoma, and mucosal neuromas. The rarest clinical form of MEN-2 is familial MTC (FMTC), which is also associated with MTC, but other endocrinopathies are characteristically not present. Each clinical form of MEN-2 results from a specific RET gene mutation, with a strong correlation of phenotype expression with regard to the onset and course of MTC and the presence of other endocrine tumors and a corresponding genotype. Recommendations for screening of RET mutations are necessary as their presence or absence will influence interventional strategies such as the timing of a prophylactic thyroidectomy and extent of surgery. Timing of screenings and development of interventional strategies are extremely important in caring for patients with certain RET mutations as evidence of metastatic MTC has been documented as early as 6 years of age. Interventional strategies should consider the risks of complications of these interventions based on certain characteristics of each individual case such as age of the patient, course of disease in affected family members, and the invasiveness of any proposed surgical procedure.

Autoimmune thyroid disease (AITD), including Graves' disease (GD) and Hashimoto's thyroiditis (HT), is one of the most common of the immune-mediated diseases. To further investigate the genetic determinants of AITD, we conducted an association study using a custom-made single-nucleotide polymorphism (SNP) array, the ImmunoChip. The SNP array contains all known and genotype-able SNPs across 186 distinct susceptibility loci associated with one or more immune-mediated diseases. After stringent quality control, we analysed 103 875 common SNPs (minor allele frequency >0.05) in 2285 GD and 462 HT patients and 9364 controls. We found evidence for seven new AITD risk loci (P < 1.12 × 10(-6); a permutation test derived significance threshold), five at locations previously associated and two at locations awaiting confirmation, with other immune-mediated diseases.

Background: Fine needle aspiration (FNA) with cytologic evaluation is the most reliable tool for malignancy prediction in thyroid nodules, but cytologic diagnosis remains undetermined for 20% of nodules., Aim: We investigated the diagnostic potential of a set of 6 marker genes to distinguish benign and malignant thyroid nodules., Subjects and Methods: The prospective study included 153 thyroid samples obtained by FNA of thyroid nodules from 151 patients (56 benign, 43 malignant, and 54 nodules with undetermined cytology). Gene expression was evaluated by quantitative realtime PCR and statistical analysis of data was performed. All samples were analyzed for V600E BRAF mutation., Results: A decrease in TTF3 and HGD1 expression was observed in malignant nodules with respect to benign ones, while an increase in PLAB expression was demonstrated in these nodules. The decision model was valid for 88 of 99 cases of benign and malignant nodules, with a total of 11 false positive or negative predictions. The obtained malignant/benign phenotype prediction was also valid for 37 of 54 cases of nodules with undetermined cytology with a total of 8 false positive and 9 false negative predictions. V600E BRAF gene mutation was demonstrated in 19/43 malignant nodules, in 0/56 benign nodules, and in 1/54 undetermined nodules., Conclusions: The expression profiles of genes (TFF3, HGD1, and PLAB) allowed a good prediction for the differentiation of benign thyroid lesions and thyroid cancer starting from cells of FNA; however, this assay showed limitations when applied to discriminate thyroid nodules with undetermined cytology.

Thyroid dysfunction (TD) is a very common entity in clinical practice nowadays. Prevalence may be underestimated because of the limitations of epidemiological studies. There are mainly genetic and environmental factors that interact on thyroid function. Genetic factors are extensively described in literature but molecular advance on the field may change older classifications based on B-cell or T-cell mediated disorders. The dominant pattern of inheritance makes family predisposition a relevant question in patient medical history but clinical research show that immune system is not enough to cause overt dysfunction. The role of environmental factors generates debate on medical literature. Some classic factors as iodine intake are well characterized but others as fetal microhimerism or new antineoplastic agents are less known. A review of medical literature on thyroid dysfunction has been performed and genetic and environmental factors are described in this article.

Background: Gene-expression analysis is increasingly important in biological research, with real-time reverse transcription PCR (qRT-PCR) becoming the method of choice. The selection of reference genes is critical for gene expression studies because the expression of these genes may vary among tissues or cells and may change under certain circumstances. However there has not been any study that compares the stability of these reference genes in human thyroid specimens. Therefore, the authors studied the stability values and the appropriate reference genes expressed in thyroid specimens., Material and Method: 25 human thyroid specimens were prospectively collected and extracted for their RNA. The candidate reference genes (hypoxanthine phosphoribosyl-transferase1 (HPRT1), ribosomal protein LI3a (RPLIA), beta-2-micro-globulin (B2M), beta-actin (ACTB) and glyceraldehyde-3-phosphate dehydrogenase (GAPD)) were amplified from these thyroid specimens using real-time RT-PCR. The stabilities of these candidate reference genes were analyzed using Normfinder software., Results: The authors found that HPRT1 has the highest stability value (40.38 x 10(9)) while GAPD has the lowest stability value (85.46 x 10(7)). Therefore GAPD is the most stably expressed gene in thyroid specimens., Conclusion: Of the 5 genes studied, GAPD was found to be the best reference gene for gene expression studies in the thyroid gland. The present results may facilitate the choice of reference genes for expression studies in thyroid diseases.

The article presents results obtained in study of relationship between polymorph variants of CYP1A1 and CYP1A2 genes with reproductive and thyroid diseases risk in female workers of petrochemical industry, when compared with reference group females. Variants TD and DD of CYP1A2 gene appeared to be associated with nodes formation in uterus and breast in female workers and reference group females. Following liability markers are obtained: homozygous in rare allele genotype CC of CYP1A1 gene for reproductive and thyroid diseaes (fibrous cystic mastopathy and nodular goitre), heterozygous genotype AG of CYP1A1 gene in uterine myoma and fibrous cystic mastopathy, homozygous in deleted T genotype of CYP1A2 gene in autoimmune thyroiditis. Occupational hazards and long length of service at hazardous industries increase effects of rare alleles of the genes studied.

Context: Heterozygous mutations in the TSH receptor gene (TSHR) are associated with partial TSH resistance, characterized by isolated nonautoimmune hyperthyrotropinemia (NAHT). The prevalence and management of this condition is controversial., Objective: Our objective was to investigate the prevalence and clinical impact of TSHR alterations in a large series of pediatric patients with NAHT and to dissect their mechanism of action., Design and Setting: For this prospective multicenter study, clinical data and samples were collected in the clinical units and conveyed to a centralized laboratory for analysis., Patients: Subjects included 153 unrelated patients with NAHT aged <18 yr. Exclusion criteria included thyroid dysgenesis or major associated congenital defects., Main Outcome Measures: Parameters of thyroid function, TSHR gene analysis, and TSHR functional assays were evaluated., Results: The frequency of heterozygous nonpolymorphic TSHR variations was 11.8%. We identified seven previously unknown variations: a frameshift (p.Q33PfsX46), one intronic (g.IVS4+2A→G), and five novel missense (p.P162L, p.Y466C, p.I583T, p.I607T, and p.R609Q) variations. The missense variations variably affected TSHR membrane expression and G(s) and/or G(q/11) signaling. Several variations cosegregated with NAHT in the affected families. Parameters of thyroid function were similar between affected and unaffected family members., Conclusions: Nonpolymorphic alterations in the TSHR gene are commonly associated with isolated NAHT in young patients, thus configuring partial TSH resistance as the most frequent inheritable cause of isolated NAHT. The identification of TSHR defects may thus be helpful for a tailored management of subclinical hypothyroidism. We provide further evidence that besides the well-known defects in G(s) signaling, TSHR genetic alternations found in NAHT may frequently impair the G(q/11) pathway.

Brain-lung-thyroid disease is a rare familial disorder caused by mutations in thyroid transcription factor 1, a gene that regulates neuronal migration. We report the clinical features of ten patients from a single family with a novel gene mutation, including observations regarding treatment. Neurologic features of the kindred included developmental delay, learning difficulties, psychosis, chorea, and dystonia. Three patients had a history of seizure, which has not been previously reported in genetically confirmed cases. Low-dose dopamine-receptor blocking drugs were poorly tolerated in 2 patients who received this therapy, levodopa improved chorea in 3 of 4 children, and diazepam was markedly effective in a single adult patient. Chorea related to brain-lung-thyroid disease appears to respond paradoxically to antidopaminergic drugs. The unusual therapeutic response seen in our patients and others may help elucidate how disease-related migratory deficits affect neural pathways associated with motor control.

Introduction: Apart from the environmental risk factors for differentiated thyroid carcinoma (DTC), such as iodine deficiency and ionising radiation, it seems that there are also other, biological risk factors, for example, familial predisposition to thyroid disease., Objectives: The aim of the study was to assess the occurrence of thyroid disease in the families of patients with DTC., Patients and Methods: A case-control study was conducted in a group of 232 patients with DTC and in 342 age- and sex-matched healthy subjects. Eighty patients were diagnosed with follicular thyroid carcinoma, 127 with papillary thyroid carcinoma, and 25 with oxyphilic thyroid carcinoma. The questionnaire included questions on the presence of thyroid diseases in first-degree relatives. The relative risk of DTC and the effect of factors associated with thyroid diseases in the family were assessed by the logistic regression model., Results: Thyroid disease was more common in the families of DTC patients than in the control group: 18.5% of the patients and 9.6% of the control group had a parent with thyroid disease (OR = 2.12, 95% CI: 1.26-3.55); 16.8% of the patients and 7.7% of the control group had a sibling with thyroid disease (OR = 2.27, 95% CI: 1.31-3.95)., Conclusions: Familial thyroid disease may be a risk factor for DTC. A positive family history of thyroid disease is associated to a larger extent with the development of papillary thyroid carcinoma than with that of follicular thyroid carcinoma.

Background: Recently, the association of a common STAT4 haplotype with type 1 diabetes (T1D) as well as rheumatoid arthritis has been documented in Caucasians and Koreans. STAT4 is involved in the signalling of interleukin-12 and γIFN, as well as interleukin-23. To discover genes affecting the susceptibility of common autoimmune diseases, we studied the association of polymorphisms in STAT4 with autoimmune thyroid disease (AITD) as well as T1D in the Korean population., Subjects and Methods: Four single-nucleotide polymorphisms on the chromosome 2q (rs11889341, rs7574865, rs8179673, and rs10181656), which were found to associate with rheumatoid arthritis were examined for association in a Korean sample of 428 AITD, 418 T1D patients, and 1060 controls., Results: The minor alleles of all four single-nucleotide polymorphisms and the reconstructed STAT4 haplotypes conferred significant degree of risk for AITD (p=10(-2) to 10(-4)). Although we found a weak association of rs11889341 with T1D (p<0.05), the same haplotypes were not associated with T1D susceptibility. When we stratified T1D patients according to the age of onset, the minor alleles of all four single-nucleotide polymorphisms and the same haplotypes showed significant association with the susceptibility of T1D in the early-onset subgroup (p<0.01), not in the late-onset subgroup., Conclusion: STAT4 alleles and the same haplotypes might influence cytokine signalling, and therefore the development of AITD as well as T1D. These results reinforce the influence of STAT4 gene as a general autoimmune gene., (Copyright © 2011 John Wiley & Sons, Ltd.)

Thyroid stimulating hormone receptor (TSHR) is thought to play a critical role in the pathogenesis of certain thyroid diseases, including Graves' disease (GD), multinodular thyroid goiter (MTG), and Hashimoto's thyroiditis (HT). In order to understand whether single nucleotide polymorphisms in the TSHR gene contribute to thyroid diseases, we have conducted a case-control study in which, we examined 8 TSHR gene single-nucleotide polymorphisms in introns 1, 4, 5, 6 and exons 7 and 8, respectively, among patients with thyroid diseases. These included one family with GD (3 patients and 9 healthy members); 60 patients with familiar thyroid diseases (30 with GD, 20 with MTG, and 10 with HT patients), 48 sporadic patients with GD and 96 healthy control individuals. Direct sequencing of all 10 exons and part of introns of TSHR gene, in these patients as well as healthy controls revealed eight polymorphisms. A novel polymorphism in exon 8 AGA(Arg) → CGA(Arg). However, there were no significant differences between patients and controls in the incidence of these polymorphisms. These results suggest that the polymorphisms (polymorphism in intron 1 at 81 bp upstream of exon 2; polymorphism in intron 4 at 135 bp upstream of exon 5; polymorphism in intron 4 at 365 bp upstream of exon 5; polymorphism in intron 5 at 69 bp upstream of exon 6; means polymorphism in intron 6 at 13 bp downstream of exon 6; polymorphism in intron 6 at 187 bp upstream of exon 7; E7+16: polymorphism in 16 bp of exon 7; polymorphism in 40 bp of exon 8) of the TSHR gene may not contribute to the pathogenesis of thyroid diseases.

The TSH receptor is a key element of thyroid homeostasis and many gain or loss of function mutations have been described since its cloning in 1989. Behind classical and severe forms like toxic adenomas, non-autoimmune familial or sporadic hyperthyroidism or inversely complete TSH resistance syndromes, new methodological approaches allow now the functional characterization of milder clinical situations : linear regression analysis of activating mutations can differentiate mutations with moderate constitutive activity and non functional receptor's variants ; the early oligomerization of wild-type and mutated receptors in intracellular compartments explain the dominant inheritance of mild form of TSH resistance. However many aspects of TSH receptor signalization remain to be explored, for example its persistent activity after internalization, and their clinical implications to be determined. Finally, new modulators of TSH receptor with attractive therapeutic potential are being developed., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)

Cytological examination of fine needle aspiration biopsy is the primary means for distinguishing benign from malignant nodules. However, as inconclusive cytology is very frequent, the introduction of molecular markers in the preoperative diagnosis of thyroid nodules has been proposed in recent years. In this article, we review the clinical implications of preoperative detection of rearrangements of the RET gene (RET/papillary thyroid carcinoma (PTC)) in thyroid nodules. The prevalence of RET/PTC in PTC depends on the histological subtypes, geographical factors, radiation exposure, and detection method. Initially, RET/PTC was considered an exclusive PTC hallmark and later it was also found sporadically in benign thyroid lesions. More recently, the very sensitive detection methods, interphase fluorescence in situ hybridization (FISH) and Southern blot on RT-PCR amplicons, demonstrated that the oligoclonal occurrence of RET rearrangement in benign thyroid lesions is not a rare event and suggested that it could be associated with a faster enlargement in benign nodules. For this reason, RET/PTC cannot be considered as an absolute marker of PTC, and its diagnostic application must be limited to assays able to distinguish between clonal and oligoclonal expression. Detection of RET/PTC by quantitative assays will be useful for diagnostic purposes in cytology specimens when a precise cutoff will be fixed in a clinical setting. Until that time, less sensitive RET/PTC detection methods and FISH analysis remain the most appropriate means to refine inconclusive cytology. Future studies with a long follow-up will further clarify the clinical significance of low level of RET rearrangements in benign nodules.

Endocrine disorders are common in infants in the neonatal ICU. They often are associated with prematurity, low birth weight or very low birth weight, and small size for gestational age. They also frequently occur in infants who are critically ill or stressed. This article describes the most common conditions and current knowledge regarding management., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Autoimmune thyroid diseases (AITD) arise from complex interactions between genetic, epigenetic, and environmental factors. Whole genome linkage scans and association studies have established thyroglobulin (TG) as a major AITD susceptibility gene. However, the causative TG variants and the pathogenic mechanisms are unknown. Here, we describe a genetic/epigenetic mechanism by which a newly identified TG promoter single-nucleotide polymorphism (SNP) variant predisposes to AITD. Sequencing analyses followed by case control and family-based association studies identified an SNP (-1623A→G) that was associated with AITD in the Caucasian population (p = 0.006). We show that the nucleotide substitution introduced by SNP (-1623A/G) modified a binding site for interferon regulatory factor-1 (IRF-1), a major interferon-induced transcription factor. Using chromatin immunoprecipitation, we demonstrated that IRF-1 binds to the 5' TG promoter motif, and the transcription factor binding correlates with active chromatin structure and is marked by enrichment of mono-methylated Lys-4 residue of histone H3, a signature of active transcriptional enhancers. Using reporter mutations and siRNA approaches, we demonstrate that the disease-associated allele (G) conferred increased TG promoter activity through IRF-1 binding. Finally, treatment of thyroid cells with interferon α, a known trigger of AITD, increased TG promoter activity only when it interacted with the disease-associated variant through IRF-1 binding. These results reveal a new mechanism of interaction between environmental (IFNα) and genetic (TG) factors to trigger AITD.

Background: Osteoprotegerin (OPG), receptor activator of nuclear factor kappaB (RANK), RANK ligand (RANKL), and TNF related apoptosis inducing ligand (TRAIL) are the key proteins in the development of bone metastases. Osteoprotegerin improves tumor cell survival and inhibits TRAIL induced apoptosis of cancer cell lines. It also binds to RANKL and inhibits its interaction with RANK (cell surface receptor), which influences osteoclast formation and function. The aim of the present study was to characterize the expression of OPG, RANK, RANKL, and TRAIL in benign and malignant thyroid tissue and thyroid cell lines., Methods: Archived thyroid tissue from 79 patients (60 differentiated thyroid cancers and 19 benign thyroids) was stained for OPG, RANK, RANKL, and TRAIL by immunohistochemistry. Staining was assessed semiquantitatively and correlated with pathology. Western blots were performed on three human thyroid cell lines: Nthy-ori 3-1 (thyroid follicular epithelium), FTC-133 (follicular thyroid carcinoma), and K1E7 (subclone of papillary thyroid carcinoma)., Results: Osteoprotegerin and RANKL staining was cytoplasmic; RANK staining was nuclear; and TRAIL staining was predominantly cytoplasmic. All four proteins were expressed in benign and malignant tissue. There was significant difference in RANK expression between malignant and benign tissue (8 vs. 84%, respectively; Fisher's exact test; P < 0.001). RANKL expression was significantly increased in malignant tissue (Fisher's exact test; P = 0.04). Western blotting showed OPG expression in all cell lines and TRAIL in none. RANK and RANKL were not detected in papillary and follicular cell lines, respectively., Conclusions: Nuclear expression of RANK protein in thyroid tissue is paradoxical; it could be due to nuclear migration after ligand binding. Suppression of RANK and increased expression of RANKL in malignant tissue warrant further investigation.

Background: Thyroid hormones have important roles in growth, development and control of metabolism, and their dysregulation can lead to disease., Objectives: To identify genes contributing to hyperthyrotropinaemia., Design, Setting, Participants: Linkage and association analyses using 1258 individuals from three Alpine villages., Outcome Measures: The study applied two different upper limits of the reference range (URR) for serum thyroid stimulating hormone (TSH) values (TSH ≥4.6 mU/l and TSH >3.0 mU/l), along with normal or low fT4 (free thyroxine) values or thyroid medical treatment to define two groups of individuals for analysis: one hyperthyrotropinaemic or high-TSH (H-TSH) (TSH ≥4.6 mU/l) group; and a larger group (TSH >3.0 mU/l) called hyperthyrotropinaemic and upper reference range TSH (H+URR-TSH)., Results: Non-parametric genome-wide linkage analysis was performed on pedigrees generated from the two groups. Linkage analysis in the H+URR-TSH group revealed a significant peak on chromosome 3q28-q29 (LOD 3.34) and a suggestive linkage peak on chromosome 6q26-27 (LOD 2.66). Analysis in the smaller hyperthyrotropinaemic (H-TSH) group supported linkage to chromosome 6q26-27. Single SNP and gene based SNP association analyses under the linkage peaks identified the PDE10A and DACT2 genes as candidates at the chromosome 6 locus., Conclusions: PDE10A or DACT2 were identified as candidate genes contributing to hyperthyrotropinaemia (and possibly hypothyroidism) in this sample. Studies in additional populations support association of variants at this locus with TSH values, especially in the PDE10A gene. Genetic linkage in families with hyperthyrotropinaemia suggests the presence of functional variants that contribute to pathological disruption of the hypothalamus-pituitary-thyroid axis.

Thyroid disease and type 1 but also type 2 diabetes mellitus (DM) are strongly associated, and this has important clinical implications for insulin sensitivity and treatment requirements. The pathophysiological basis of this association has only recently been better elucidated. It rests on a complex interaction of common signalling pathways and, in the case of type 1 diabetes and autoimmune thyroid disease, on a linked genetic susceptibility. The pathophysiological mechanisms underlying this linked regulation are increasingly being unravelled. They are exemplified in the regulation of 5' adenosine monophosphate-activated protein kinase (AMPK), a central target not only for the modulation of insulin sensitivity but also for the feedback of thyroid hormones on appetite and energy expenditure. The present review will discuss these concepts and their consequences for the clinical care of patients with DM and thyroid disorders. Moreover, it makes reference to the added effect of metformin in suppressing TSH., (© 2011 Blackwell Publishing Ltd.)

The study of the different factors regulating the bioactivity of thyroid hormones is of utmost relevance for an adequate understanding of the glandular pathophysiology. These factors must be considered by the clinician in order to achieve a successful diagnosis and treatment of glandular diseases. Among the factors regulating bioactivity of thyroid hormones are the following: A) Plasmatic membrane hormone transporters, which tissue-specific expression is responsible for the cellular uptake of hormones, B) A set of deiodinating enzymes which activate or inactivate intracellular thyroid hormone, and C) Nuclear receptors which are responsible for the different cellular responses at the transcriptional level. This review compiles analysis and discusses the most recent findings regarding the regulation of thyroid hormone bioactivity, as well as the clinical relevance of different polymorphisms and mutations currently described for membrane transporters and deiodinases. In addition, the main issues and present and future study areas are identified.

Background: Common variants in the interleukin 12B (IL12B) gene are associated with predominantly inflammatory (Th1) or antibody-mediated (Th2) immune responses. As Hashimoto's disease and Graves' disease are thought to arise from mainly Th1 and Th2 immune responses respectively, we hypothesized that IL12B genotype may influence the clinical presentation of autoimmune thyroid disease., Objective: We tested for differences in IL12B genotype between Graves' disease and Hashimoto's disease., Patients: We studied a discovery cohort of 203 Australian women and 37 men with autoimmune thyroid disease, a replication cohort of 100 European men and a cohort of 146 Chinese men., Intervention: We analysed three IL12B variants: rs41292470, in the promoter; rs3212227, in the 3' untranslated region and rs6887695, located 60 kilobases upstream from the coding region., Results: In the discovery cohort, rs41292470 and rs3212227 genotypes did not differ significantly between Hashimoto's disease and Graves' disease. In Australian men (but not women), rs6887695 genotype differed between Hashimoto's disease and Graves' disease, with a minor allele frequency (MAF) of 14% and 41%, respectively (P=0·034). This result was confirmed in the European men (MAF 24% and 41%; P=0·013). On combined analysis of Australian, European and Chinese men (N=285), the difference was highly significant (MAF 23% and 45%; P=3×10(-5) ). In 233 men without thyroid disease, the MAF was 34%, significantly different from Graves' disease (P=0·005) and Hashimoto's disease (P=0·029)., Conclusion: In men with autoimmune thyroid disease, a common variant located upstream of the IL12B coding region may influence whether patients present with Graves' disease or Hashimoto's disease., (© 2011 Blackwell Publishing Ltd.)

Unlocking the genetic contribution to autoimmune thyroid disease (AITD) will hold one of the keys to understanding disease pathogenesis and developing improved treatments. Significant increases in our understanding of the human genome combined with methodological advances in our ability to search for genetic variation have transformed the way in which we screen the genome for susceptibility loci. From early linkage analysis through to candidate gene studies and most recently genome-wide association screening, each methodology has revealed important insights into not just the heritability of AITD but also the best way of identifying disease causing DNA variants. This review will examine each of the different genome screening techniques, highlighting the successes and failures of each methodology and the lessons learnt which have helped inform the next phase of the disease-gene identification process. We will also look to see where we should be focusing our research efforts in the future.

Thyroid stimulating hormone receptor (TSHR) is a vital thyrocyte membrane protein in the thyroid gland. Thyroid Stimulating Hormone (TSH) which is a pituitary hormone is the main stimulator of thyroid gland to produce thyroid hormones, it binds with high affinity to the TSHR through weak bonds including hydrophobic, ionic, hydrogen bonds and trigger the initial steps in thyroid gland stimulation to produce the related hormones. This study was carried out at department of biochemistry of Golestan university of medical sciences. All the related articles related to TSHR modification happened due to mutations and any other alterations which affect the level of TSH-TSHR complex were studied and the main points were extracted out of the pile of information and were organized as present review. TSH-TSHR is the initial and vital step of a long process of thyroid hormone production within the thyroid gland. Any alteration on the TSH-TSHR affinity which may happen due to the direct effect of TSHR modification eventually lead to the serious adverse effects of either hypothyroidism or hyperthyroidism if the TSH-TSHR level are suppressed or elevated, respectively. The prime cause of the thyroid disorders relay on the possible modification on the biochemical structure of TSHR with subsequent alteration on the level of TSH-TSHR complex. TSHR mutation accompanied by biochemical modification, unable it to bind properly to TSH. In some other conditions such mutation leave a TSHR with either of higher affinity towards to TSH or even TSHR which can be activated in the absence of TSH. The structural modification of TSHR and alteration in the level of TSH-TSHR in the thyroid gland eventually lead to thyroid disorders either of hypothyroidism or hyperthyroidism.