Research on THRβ gene mutation in a patient with thyroid hormone resistance syndrome using whole-exome sequencing / 中华内分泌代谢杂志

Objective:To assess clinical and genetic features in a patient with thyroid hormone resistance syndrome(RTH) and explore the pathogenic mechanism.Methods:The clinical data of the proband was collected. The genomic DNA was extracted from peripheral blood samples of the patients. The pathogenic variant was identified using whole-exome sequencing and confirmed by Sanger sequencing. Then the function of the mutation sites was detected by bioinformatics.Results:The patient presented with chest distress, palpitation, and persistent atrial fibrillation, along with elevated levels of serum free triiodothyronine(FT 3), free thyroxine(FT 4), and thyroid stimulating hormone(TSH), which suggested RTH clinically. The genetic analysis identified a heterozygous mutant of THRβ(c.1313G>A) gene at exon 8, which was a missense mutation causing the substitution of arginine to histidine at 438 position of the protein(p.R438H). Its inheritance pattern was unknown. This mutation was considered as a new one that had not been reported. Conclusion:A novel pathogenic THRβ gene mutation was found in the patient with RTH, which might be the cause of this disease. This variant c. 1313G>A is located in the ligand binding domain of THRβ, which might result in low protein activity.

The Syndromes of Resistance to Thyroid Hormone Beta / 罕见病研究

The syndrome of resistance to thyroid hormone(RTH) is a rare syndrome caused by the mutation of thyroid hormone receptor (TR) gene, which reduces the sensitivity of target organs to thyroid hormone (TH) and leads to the dysfunction of TH. Thyroid hormone resistance syndrome β (RTHβ) is caused by the mutations in the THRB gene. The main characteristics of RTHβ are increased thyroxine (T4) in the circulating blood, normal or elevated levels of triiodothyronine(T3), paired with normal or high thyroid-stimulating hormone (TSH) concentration. Clinically, it is easy to misdiagnose RTHβ as hyperthyroidism, and give anti-thyroid drugs, radioactive 131I therapy or surgery, which then leads to the aggravation of TH resistance, so the correct diagnosis of the disease is critical. In this paper, the molecular mechanism, clinical characteristics, diagnosis and treatment of RTHβ are summarized.

Thyroid Hormone Resistance in a Preterm Infant with a Novel THRB Mutation

Resistance to thyroid hormone (RTH) is a condition caused by a mutation in the thyroid hormone receptor gene. It is rarely reported in individuals with no family history of RTH or in premature infants, and its clinical presentation varies. In our case, a premature infant with no family history of thyroid diseases had a thyroid stimulating hormone level of 85.0 µIU/mL and free thyroxine level of 1.64 ng/dL on a thyroid function test. The patient also presented with clinical signs of hypothyroidism, including difficulties in feeding and weight gain. The patient was treated with levothyroxine; however, only free thyroxine and triiodothyronine levels increased without a decrease in thyroid-stimulating hormone levels. Taken together with thyroid gland hypertrophy observed on a previous ultrasound examination, RTH was suspected and the diagnosis was eventually made based on a genetic test. A de novo mutation in the thyroid hormone receptor β gene in the infant was found that has not been previously reported. Other symptoms included tachycardia and pulmonary hypertension, but gradual improvement in the symptoms was observed after liothyronine administration. This report describes a case involving a premature infant with RTH and a de novo mutation, with no family history of thyroid disease.

A Case with Thyroid Hormone Resistance Syndrome

Thyroid hormone resistance is a rare syndrome of reduced tissue responsiveness to thyroid hormone. We report the case of a 13-month girl with short height and low weight. She was born at 37+6 weeks gestation and weighed 2,470 g. In the neonatal screening test, patients' thyroid stimulation hormone (TSH) level was increased to 13.1 µIU/mL. In follow-up test after getting levothyroxine medication, patients' free T4 level continued to increase and TSH level was normalized. After stop medication, the patient visited Soonchunhyang University Seoul Hospital every 2 to 3 months and done laboratory test, and the result was not changed. Despite good feeding, she consistently shows 5–10 percentile weight and 5–10 percentile height. Her bone age was delayed by 5 months compared to the expected age. In suspicious thyroid hormone resistance, THRβ gene study and brain magnetic resonance imaging (MRI), and T3 suppression test was done. Brain MRI and T3 suppression test shows the exception of pituitary thyroid adenoma. Gene study result was THRβ gene mutation, c.1012C>T (p.Arg338Trp), and heterozygous. This gene mutation was reported at thyroid hormone resistance family. After diagnosis of thyroid hormone resistance, because of the patient is asymptomatic, she does not have medication. We are checking developmental delay, growth delay, and other clinical hypothyroid symptoms.

Pedigree analysis of a pituitary-resistance to thyroid hormone syndrome family caused by heterozygous A317T mutation in thyroid hormone receptor β gene / 中华内分泌代谢杂志

To study thyroid hormone receptor β(THRβ)gene mutation in a pituitary-resistance to thyroid hormone syndrome family. The peripheral blood samples of the patient, his sister, parents, and 4 maternal relatives were collected. Then serum was isolated for detecting thyroid hormone levels with chemiluminescence immunoassay, and DNA was extracted for PCR, and 10 exons of THRβ gene were sequenced. The patient and his mother had the hyperthyroid symptom for many years and his mother with atrial fibrillation. The G→A heterozygous transition mutation was confirmed by exon sequencing at nucleotide 949 within exon 9 of THRβ gene in the patient and his mother, which was a missense mutation causing a substitution of Alanine to Threonine(A317T). No mutation was found in THRβ gene in other family members. This is the first Chinese family reported with pituitary thyroid hormone resistance syndrome caused by a A317T mutation in the thyroid hormone receptor β gene.

Clinical characteristics of thyroid hormone resistance syndrome in two cases with different subtypes / 中华儿科杂志

Objective@#To analyze the clinical characteristics of children with two types of thyroid hormone resistance (RTH) syndrome, and to detect the variants of thyroid hormone receptor alpha(TRα) and TRβ gene in children.@*Method@#Two children with RTH were reported in regard to clinical manifestation, laboratory examination and genetic variants. Some related reports in literature were reviewed.@*Result@#Case 1 was a girl, 10 years old, with thyroid enlargement for several days and without thyrotoxicosis. Laboratory work-up revealed that free thyroxine (FT4) was 65.77 pmol/L (reference 12-22) , free triiodothyronine (FT3) was 15.36 pmol/L (reference 3.1-6.8) and thyroid stimulating hormone (TSH) level was normal. There was a likely pathogenic missense variant detected in TRβ gene and this patient was diagnosed with RTHβ. Case 2 was a boy, 3 years old, with classic features of hypothyroidism(growth retardation, developmental retardation, skeletal dysplasia) but had only borderline-abnormal thyroid hormone levels. Targeted sequencing showed a de novo heterozygous nonsense variant in TRα gene which is a pathogenic variant and this patient been diagnosed with RTHα.@*Conclusion@#Thyroid enlargement is a common clinical manifestation of RTHβ, with laboratory work-up reveals elevated FT4 and FT3 levels but TSH level is normal. The clinical manifestations of RTHα are similar to those of hypothyroidism, but the thyroid hormone levels are almost normal. The gene sequence and the pathogenicity analysis for TRα and TRβ will help to make a definitive diagnosis.

One case of a thyrotropin-secreting microadenoma and resistance to thyroid hormone with P453T mutation in TRβgene / 中华内分泌代谢杂志

[Summary] We investigated a 12-year-old girl with elevated serum FT3 , FT4 , and TSH levels. The sequence of thyroid hormone receptorβ( TRβ) exons revealed a CCT→ACT transition mutation at nucleotide 453 site within exon10,whichresultedinthesubstitutionofcytosinetoadenosinein(P453T). Pituitarymagneticresonanceimage showed a pituitary micoradenoma. The patient underwent transsphenoidal pituitary adenomectomy. Pathological results exhibited positive TSH-β, GH, prolactin, ACTH, and α-HCG staining for the tumor. This is the first case report with thyroid hormone resistance syndrome and thyrotropin-secreting adenoma.

Thyroid hormone resistance with H435Y mutation in thyroid hormone receptor β: a pedigree analysis / 中华内分泌代谢杂志

[Summary] The genomic DNA was extracted from peripheral blood leukocyte of the patient with thyroid hormone resistance syndrome and 14 members of his family.The exons 1-10 of thyroid hormone receptor β (TRβ) gene were amplified by PCR.The products of PCR were sequenced directly to detect the gene mutation.The results showed that 3 members of this family were confirmed to have the C→T transition mutation at nucleotide 1 303 site within exon 10 of TRβ gene,and the missense mutation results in the substitution of histidine to tyrosine (H435Y).The heterozygous mutation may lead to the occurrence of thyroid hormone resistance syndrome.

The multiple effects of thyroid disorders on bone and mineral metabolism / Os múltiplos efeitos das disfunções tireoidianas sobre o metabolismo osteomineral

Differently from most hormones, which commonly are specialized molecules able to influence other cells, tissues and systems, thyroid hormones (TH) are pleiotropic peptides, whose primordial function is difficult to identify. The complex action of TH on human economy can be easily witnessed by examining the diverse consequences of TH excess and deficiency during development and after maturity. In particular, different manifestations in bone modeling and remodeling reflect the circumstantial consequences of thyroid disturbances, which are age dependent. While hyperthyroidism during childhood enhances bone mineralization and accelerates epiphyseal maturation, in adults it induces bone loss by predominant activation of osteoclast activity. Furthermore, the syndrome of TH resistance is a multifaceted condition in which different sites exhibit signs of hormone excess or deficiency depending on the configuration of the TH receptor isoform. The investigation of the impact of TH resistance on the skeleton still remains to be elucidated. We present here a thorough review of the action of TH on bone and of the impact of thyroid disorders, including hyper- and hypothyroidism and the syndrome of TH resistance, on the skeleton.

Diferentemente da maioria dos hormônios, que usualmente são moléculas especializadas capazes de influenciar outras células, tecidos e sistemas, os hormônios da tireoide (HT) são peptídeos pleiotrópicos, cuja função primordial é difícil de identificar. A ação complexa dos HT na fisiologia humana pode ser facilmente reconhecida ao observar as diversas consequências do excesso e da deficiência de HT durante e após o pleno desenvolvimento. Em particular as diferentes manifestações na modelação e remodelação óssea refletem que as consequências esqueléticas das disfunções tireoidianas dependem das circunstâncias e variam com a idade. Enquanto o hipertireoidismo durante a infância aumenta a mineralização óssea e acelera a maturação epifisária, em adultos induz a perda óssea pela ativação predominante da ação osteoclástica. Além disso, a síndrome de resistência ao HT é uma condição multifacetada na qual diferentes tecidos apresentam sinais de excesso ou deficiência hormonal, dependendo da predominância da expressão das diversas isoformas do receptor de HT. O impacto da resistência ao HT sobre o esqueleto ainda é motivo de investigação. Apresentamos aqui uma revisão abrangente sobre as ações ósseas dos HT e o impacto no esqueleto dos distúrbios da tireoide, incluindo hipo e hipertireoidismo e síndrome de resistência ao HT.

Resistance to thyroid hormone due to a novel mutation of thyroid hormone receptor beta gene

Resistance to thyroid hormone (RTH) is a rare inherited syndrome characterized by diminished response of the target tissue to thyroid hormone caused, in the majority of cases, by mutation of the thyroid hormone receptor beta (THRbeta) gene. Despite elevated serum levels of free thyroid hormones and thyroid stimulating hormone (TSH), the paucity of symptoms and signs of thyroid dysfunction suggest RTH. We report the case of a 9-year-old girl with goiter. Her thyroid function tests showed increased serum levels of free thyroxine, triiodothyronine, and TSH. The genetic analysis of THRbeta confirmed a novel mutation in exon 9; this was a heterozygous C-to-T change in the 327th codon, substituting threonine for isoleucine (T327I).

Síndrome de resistencia a las hormonas tiroideas: reporte de un caso / Syndrome of resistance to thyroid hormone: a case report

El síndrome de resistencia a las hormonas tiroideas es una entidad poco frecuente que se caracteriza por concentraciones elevadas de tiroxina libre y triyodotironina libre, tirotropina normal o ligeramente elevada, en ausencia de cualquier otra enfermedad, medicación o antagonista que causen alteraciones sobre la función tiroidea. Se reporta un caso de una mujer a quien se le realizó diagnóstico de resistencia a las hormonas tiroideas con base en los antecedentes personales, las manifestaciones clínicas y los hallazgos de laboratorio; además, se realiza una revisión de la literatura, con énfasis en el diagnóstico y el tratamiento de la enfermedad.

The syndrome of resistance to thyroid hormones is a rare disease characterized by high levels of both free thyroxin and free triiodothyronine, as well as normal or slightly elevated levels of thyrotropin in absence of any disease, medication or antagonist that cause alterations on thyroid function. It is reported a case of a woman who was diagnosed with syndrome of resistance to thyroid hormones based on personal history, signs and symptoms, and laboratory findings. In addition, a literature review is presented, with emphasis in diagnosis and treatment of the disease.

Monogenic Thyroid Disorder / 대한갑상선학회지

Monogenic disorder is a single gene disorder resulted of a single mutated gene. Monogenic disorder has benefits in early diagnosis and precious prediction of disease course. Furthermore, monogenic disorder could provide an informative knowledge to the understanding of related pathophysiology. Thyroid monogenic disorder could occur in various steps, such as thyroid development, hormonogenesis, TSH-receptor signaling, thyroid hormone transport and end organ response. Here, we reviewed of congenital hypothyroidism, congenital hyperthyroidism and thyroid hormone resistance syndrome.

TRβ gene mutation in a family with thyroid hormone resistance syndrome / 中华内分泌代谢杂志

Objective To detect the gene mutation of thyroid hormone receptor β ( TRβ ) in a family with thyroid hormone resistance syndrome.Methods The genomic DNA was extracted from peripheral blood leukocytes of the patient and his 5 family members.The exons 1-10 ofTRβ gene were amplified by PCR.The products of PCR were sequenced directly to detect the gene mutation.Results Two members of this family were confirmed to have the C y A transition mutation at nucleotide 1642 site within exon 10 of TRβ gene,which was a missense mutation causing the substitution of Proline to Threonine (P453T).The mutation was Heterozygous.Conclusions It was confirmed that the patient has TRβ gene mutation P453T in exon 10.The mutation may lead to the occurrence of thyroid hormone resistance syndrome.

Case of Thyroid Hormone Resistance Syndrome with a Mutation in the Thyroid Hormone Receptor Beta Gene / 대한내과학회지

In thyroid hormone resistance syndrome (THR) TSH levels are normal or elevated despite thyroid hormone levels being elevated. THR is distinguished from TSH-producing pituitary adenoma by TRH stimulation and alpha-subunit tests, thyroid hormone receptor (TR) beta gene analysis, and sellar MRI. A 24-year old man with diffuse goiter visited our hospital complaining of fatigue, heat intolerance, palpitation, and weight loss. He had elevated total T3 and free T4 levels, but normal TSH levels. Serum TSH levels during TRH stimulation tests performed before and after T3 suppression showed normal and non-suppressible responses, respectively. The serum basal alpha-subunit test result was normal. A TR beta gene R438H mutation was identified, and a pituitary mass with cystic change was identified by sellar MRI. We report a case of THR with a mutation (R438H) in the TR beta gene, the first case of its kind in Korea.

A Case of Resistance to Thyroid Hormone with Thyroid Cancer

Resistance to thyroid hormone (RTH) is an autosomal dominant hereditary disorder that is difficult to diagnose because of its rarity and variable clinical features. The magnitude of RTH is caused by mutations in the thyroid hormone receptor beta (TRbeta) gene. We recently treated a 38-yr-old woman with RTH who had incidental papillary thyroid carcinoma. She presented with goiter and displayed elevated thyroid hormone levels with an unsuppressed TSH. She was determined to harbor a missense mutation of M310T in exon 9 of the TRbeta gene, and diagnosed with generalized RTH. This mutation has not yet been reported in Korea. RTH is very rare and easily overlooked, but should be considered in patients who present with goiter and elevated thyroid hormone levels with an unsuppressed TSH. The association between thyroid cancer and RTH needs further study.

Two cases of thyroid hormone resistance syndrome with review of literature / 中华内分泌代谢杂志

The clinical features,laboratory data,and therapeutic efficacy of two patients with thyroid hormone resistance syndrome(THRS)were reported.Two cases manifested growth retardation,raised serum TT_3,FT_3levels,and decreased~(131)I uptake.One patient presented with bird face deformity,nerve deafness,and raised TSH level.The superphysiological dosage of exogenous thyroxin inhibited the synthesis and release of thyrotropin.Thyroxin treatment proved to be effective for the patients.THRS is a disease related to thyroid hormone receptor gene mutation.The final diagnosis of this disease depends on gene analysis.

Molecular Aspects of Congenital Hypothyroidism / 대한소아내분비학회지

Recent studies have identified molecular genetic defects in some cases of congenital hypothyroidism as well as in a few cases of central hypothyroidism. These studies have brought to light hitherto unexplained forms of both these disorders. In spite of early diagnosis by screening of newborns infants and early treatment, some patients with congenital hypothyroidism do not show normal mental development. This finding was subsequently attributed to molecular defects in transcription factors, which are important for both the embryonic development of the thyroid gland as well as the development of other organs, including the organs of the central nervous system (CNS). These findings will facilitate the understanding of the critical role of thyroid hormones in pre- and postnatal CNS development. However, the molecular basis of thyroid dysgenesis in most cases remains to be elucidated, and the identification and analysis of familial cases will be very useful for defining additional mechanisms of thyroid dysgenesis. In fact, these studies may provide crucial evidence for genetic counseling, as suggested by the possible dominant mode of inheritance of some forms of congenital hypothyroidism. This review focuses on the most recent advance in our understanding of the molecular basis of primary congenital hypothyroidism.

A novel mutation of thyroid hormone receptor beta (I431V) impairs corepressor release, and induces thyroid hormone resistance syndrome / Uma nova mutação no TR beta (I431V) prejudica a liberação de correpressores e induz síndrome de resistência ao hormônio tireoideano

Resistance to thyroid hormone (RTH) is a rare disorder characterized by variable tissue hyporesponsiveness to thyroid hormone, usually caused by mutations in the thyroid hormone receptor beta (TRβ). We describe a large Brazilian family harboring a novel mutation affecting TRβ gene and inducing RTH. A 14-year-old girl was found to have elevated free T4 and free T3 plasma concentrations in coexistence with unsuppressed TSH and a questionable goiter. The diagnosis of RTH was verified by identification of a novel mutation (I431V) in the TRβ gene. Sixteen asymptomatic relatives of the proposita are also affected by the mutation. Functional studies showed that I431V mutation exerts dominant-negative effect on wild type TRβ, mainly by impairment of ligand-dependent release of corepressor SMRT. The presence of this mutation reduces potency, but does not affect efficacy of thyroid hormone action, in accordance with the clinical picture of eumetabolism of the affected individuals.

A resistência ao hormônio tireoideano (RHT) é uma doença rara, causada por variável hiporresponsividade dos tecidos aos hormônios tireoideanos, usualmente causada por mutações no receptor beta do hormônio tireoideano (TRβ). Descrevemos uma grande família brasileira portadora de uma nova mutação afetando o gene do TRβ, induzindo RHT. Uma paciente de 14 anos de idade apresentou concentrações plasmáticas elevadas de T4 e T3 livres, associadas a TSH não-suprimido e bócio questionável. O diagnóstico de RHT foi estabelecido pela identificação da mutação I431V no gene do TRβ. Dezesseis parentes assintomáticos da probanda também são afetados pela mutação. Estudos funcionais mostram que a mutação I431V exerce efeito dominante negativo sobre o TR selvagem, basicamente, por prejudicar a liberação do correpressor SMRT ligante-dependente. A presença desta mutação reduz a potência, mas não afeta a eficácia da ação do hormônio tireoideano, o que está de acordo com a apresentação clínica de eumetabolismo dos indivíduos afetados.

Resistencia a la hormona tiroidea y embarazo: caso clínico / Thyroid hormone resistance syndrome and pregnancy: case report

Thyroid hormone resistance syndrome is a genetic disease determined by a mutation that modifies the configuration of the beta thyroid hormone receptor, affecting its T3 binding capacity. Increased T3 and T4, determined by a compensatory TSH elevation secondary to pituitary resistance, allows an euthyroid functional state in most of the cases. The coexistence of pregnancy and thyroid hormone resistance is uncommon. Therefore, the optimal diagnosis and treatment strategy has not been determined. We report a 32 years old woman with thyroid hormone resistance, that became pregnant. During her pregnancy, she wassupplemented with levothyroxine in doses of 50 to 60 ug/day and remained euthyroid. Fetal development and growth were normal.

Progress in the study of molecular mechanisms in thyroid hormone insensitive syndrome / 中华内分泌代谢杂志

Thyroid hormone insensitive syndrome is an inherited disease characterized by decreased target tissue responsiveness to thyroid hormone. Most cases are due to thyroid hormone receptor β gene mutation. Two novel types of thyroid hormone insensitive syndrome were recently identified, which are caused by gene mutations of MCT8, a specific thyroid hormone transporter, and SBP2 in the synthesis of deiodinase.