Resistance to thyroid hormone associated with autoimmune thyroid disease in a Turkish family

Graves' disease coexisted with resistance to thyroid hormone: a case report

Background

Resistance to thyroid hormone is a rare autosomal dominant disorder characterized by reduced responsiveness to thyroid hormone and can cause syndrome of inappropriate secretion of thyroid stimulating hormone. Although Graves’ disease is a common autoimmune thyroid disorder, the coexistence of these two diseases is extremely rare and makes the diagnosis and treatment complicated, leading to the delayed diagnosis of resistance to thyroid hormone. We describe the case of a Japanese man with resistance to thyroid hormone coexisting with Graves’ disease, in which the correct diagnosis of resistance to thyroid hormone was delayed by masking of the signs of syndrome of inappropriate secretion of thyroid stimulating hormone, with final diagnosis 30 years after the initial treatment for Graves’ disease.

Case presentation

A 30-year-old Japanese man presented with diffuse goiter and thyrotoxicosis. Anti-thyroid stimulating hormone receptor antibody was positive. He was diagnosed with Graves’ disease. Anti-thyroid medication was chosen as the initial treatment for Graves’ disease. However, this treatment failed to normalize the free triiodothyronine, free thyroxine, and thyroid stimulating hormone levels. His thyroid hormone levels indicated syndrome of inappropriate secretion of thyroid stimulating hormone. After cessation of methimazole treatment by remission of Graves’ disease, his state of syndrome of inappropriate secretion of thyroid stimulating hormone persisted. Magnetic resonance imaging revealed no pituitary tumor lesions. The results of thyroid stimulating hormone-releasing hormone stimulation test showed a normal response of thyroid stimulating hormone. He was suspected to have resistance to thyroid hormone. Direct sequencing analysis of the thyroid hormone receptor β gene identified a heterozygous missense mutation, R282S. Coexistence of resistance to thyroid hormone with Graves’ disease was confirmed. He has no signs of thyrotoxic symptoms, and is capable in activities of daily living at the present time.

Conclusion

We described a rare case of resistance to thyroid hormone simultaneously existing with Graves’ disease. This case demonstrated that these diseases can coexist, and indicated some of the difficulties in diagnosis of resistance to thyroid hormone with coexisting Graves’ disease. The diagnosis of resistance to thyroid hormone did not become apparent until after anti-hyperthyroidism treatment. Although rare, careful follow-up after the initial treatment of Graves’ disease is necessary. The coexistence of these two diseases should be considered in patients showing occasional syndrome of inappropriate secretion of thyroid stimulating hormone.

Coexistence of Autoimmune Hyper- and Hypothyroidism in a Kindred with Reduced Sensitivity to Thyroid Hormone

INTRODUCTION

Resistance to thyroid hormone beta (RTHβ) is a rare disease with an autosomal dominant transmission. Diagnosis may be challenging especially in patients with hyper- or hypothyroidism.

CASE PRESENTATION

A 31-year-old male patient with suppressed thyroid-stimulating hormone (TSH), elevated free thyroxine and free triiodothyronine, along with high thyroid receptor antibodies was diagnosed with Graves' disease. Benzylthiouracil was started. One month later, reduced sensitivity to thyroid hormones was suspected because of persistently high thyroid hormone levels contrasting with high TSH level. Molecular analysis highlighted a 10c.1357C>T p.P453S mutation in the thyroid hormone receptor beta gene (THRB). RTHβ was diagnosed. Several relatives also had RTHβ (the mother, the young son, and 2 out of 3 siblings). Autoimmune hypothyroidism was present in the mother, whereas 2 out of 3 siblings had asymptomatic autoimmunity.

DISCUSSION/CONCLUSION

Both Graves' disease and autoimmune hypothyroidism were described in patients with RTHβ. We show here for the first time that autoimmune hypo- and hyperthyroidism may coexist in kindred with RTHβ. Seven previously published cases of Graves' disease and RTHβ were retrieved and analyzed. Treatments and thyroid hormone level targets are discussed as well as the possible link between RTHβ and autoimmune thyroid diseases.

Genomic test ends a long diagnostic odyssey in a patient with resistance to thyroid hormones

Background

Resistance to thyroid hormones is a very rare condition, which is often misdiagnosed and mistreated. The cases where there is a concomitant autoimmune thyroid disorder are ultra-rare and particularly challenging to treat. Diagnostic and research-based genomic testing can sometimes identify pathogenic variants unrelated to the primary reason for testing (incidental findings).

Case presentation

We present a patient with thyroid resistance associated with hypothyroid Hashimoto thyroiditis. The long diagnostic odyssey spanning over 20-years included repeated misdiagnoses and mistreatments and was concluded by a research-based genomic testing, identifying a “de novo” THRB pathogenic variant. The varying sensitivity of various tissues to thyroid hormones accompanied by hypothyroid Hashimoto thyroiditis continues to pose a significant treatment challenge.

Conclusions

Thyroid hormone resistance continues to be an un(der)- and misdiagnosed thyroid condition whose management is particularly challenging when associated with autoimmune thyroid disease. Whole exome sequencing has the potential to identify THRB pathogenic variants as incidental findings. Reporting such secondary findings from genomic testing may be particularly important in the context of the rarity of the condition and the potential clinical consequences of misdiagnosis and mistreatment.

BRAFV600E mutation contributes papillary thyroid carcinoma and Hashimoto thyroiditis with resistance to thyroid hormone: A case report and literature review

Resistance to thyroid hormone (RTH) is a rare autosomal hereditary disorder characterized by increased serum thyroid hormone (TH) levels with unsuppressed or increased thyrotropin concentration. It remains unknown whether the coexistence of RTH with papillary thyroid carcinoma (PTC) and Hashimoto thyroiditis (HT) is incidental or whether it possesses a genetic or pathophysiological association. In the present study, a case of RTH with PTC and HT in an 11-year-old Chinese patient was examined and the clinical presentation of RTH with PTC was discussed. In addition, the possible associations between RTH, PTC and HT were determined. HT was confirmed in the patient using an autoimmune assay and thyroid ultrasound. RTH was diagnosed on the basis of clinical manifestations, laboratory information and gene analysis, and PTC was diagnosed according to histological results. Results of BRAF^V600E mutation analysis were positive. A literature review of 14 cases of RTH with PTC was included for comparison. The present case report indicates an association of RTH with PTC and HT coexistence in the patient. Close follow-up, histological evaluation and BRAF^V600E mutation detection should be performed in each RTH case with HT, since a persistent increase in TSH may be a risk factor for the development of thyroid neoplasm.

A Case of Resistance to Thyroid Hormone (RTH) with a Negative Family History with Diagnosis Based on Persistent Palpitations

Approximately 140 different mutations of thyroid hormone receptor β (TRβ) have been identified in resistance to thyroid hormone (RTH). We report herein a middle-aged man with a negative family history who was diagnosed with RTH based on persistent palpitations. Genetic analysis showed a TRβ mutation causing the substitution of alanine for proline 453 (P453A) in exon 10. Since treatment of RTH is different from that of Graves' disease and thyroid stimulating hormone-producing adenoma (TSHoma), a genetic analysis should be performed even in patients who have a negative family history of RTH and who are free of TSHoma when they present with persistent inappropriate secretion of thyroid stimulating hormone (SITSH).

Autoimmune Abnormalities of Postpartum Thyroid Diseases

The year following parturition is a critical time for the de novo appearance or exacerbation of autoimmune diseases, including autoimmune thyroid disease. The vast majority of postpartum thyroid disease consists of postpartum thyroiditis (PPT) and the minority by Graves' disease and non-autoimmune thyroiditis. PPT has a worldwide prevalence ranging from 1 to 22% and averaging 5% based on a review published in 2012. Several factors confer risk for the development of PPT. Typically, the clinical course of PPT is characterized by three phases: thyrotoxic, hypothyroid, and euthyroid phase. Approximately half of PPT women will have permanent hypothyroidism. The best humoral marker for predictivity, already during the first trimester of gestation, is considered positivity for thyroperoxidase autoantibodies (TPOAb), though only one-third to half of such TPOAb-positive pregnant women will develop PPT. Nutraceuticals (such as selenium) or omega-3-fatty acid supplements seem to have a role in prevention of PPT. In a recent study on pregnant women with stable dietary habits, we found that the fish consumers had lower rates of positivity (and lower serum levels) of both TPOAb and thyroglobulin Ab compared to meat eaters. Finally, we remind the reader of other diseases that can be observed in the postpartum period, either autoimmune or non-autoimmune, thyroid or non-thyroid.

Syndrome of Reduced Sensitivity to Thyroid Hormones: Two Case Reports and a Literature Review

Resistance to thyroid hormone (RTH) is an extremely rare dominantly inherited condition of impaired tissue responsiveness to thyroid hormone (TH). Most patients with RTH have mutations in the gene that encodes the β isoform of the receptor of thyroid hormone (THR-β gene). Mutant receptors are unable to activate or repress target genes. The majority of them are asymptomatic or rarely have hypo- or hyperthyroidism. RTH is suspected by the finding of persistent elevation of serum levels of free T3 (FT3) and free T4 (FT4) and nonsuppressed TSH. We present two cases of RTH diagnosed after total thyroidectomy. The first patient was initially diagnosed with primary hyperthyroidism due to toxic multinodular goiter. The second patient had undergone thyroidectomy for multinodular goiter 16 years before diagnosis of RTH. After thyroidectomy, although on relatively high doses of levothyroxine, both of them presented with the laboratory findings of RTH. Genetic analysis revealed RTH.

Thyroid profiles in a patient with resistance to thyroid hormone and episodes of thyrotoxicosis, including repeated painless thyroiditis

BACKGROUND

Thyrotoxic disease can be difficult to recognize in patients with resistance to thyroid hormone (RTH) because the clinical symptoms of thyrotoxicosis cannot be observed, and thyrotropin (TSH) may not be suppressed because of hormone resistance. Painless thyroiditis is a relatively common cause of thyrotoxicosis, but its occurrence in RTH has not been reported. We assessed the thyroid profile in a patient with RTH and episodes of thyrotoxicosis who experienced repeated painless thyroiditis.

PATIENT FINDINGS

A 44-year-old Japanese woman with RTH, which was confirmed by the presence of a P453A mutation in the thyroid hormone receptor β (TRβ) gene, showed a slight elevation of the basal levels of thyroid hormones, which indicated that her pituitary RTH was mild. She experienced a slight exacerbation of hyperthyroxinemia concomitant with TSH suppression. A diagnosis of painless thyroiditis was made because of the absence of TSH receptor antibodies, low Tc-99m pertechnetate uptake by the thyroid gland, and transient suppression followed by a slight elevation of TSH following the elevation of thyroid hormones. The patient's complaints of general malaise and occasional palpitations did not change throughout the course of painless thyroiditis. Three years later, painless thyroiditis occurred again without any deterioration of the clinical manifestations.

CONCLUSIONS

Mild pituitary RTH can be overcome by slight exacerbation of hyperthyroxinemia during mild thyrotoxicosis. When pituitary resistance is severe and TSH is not suppressed, thyrotoxicosis may be overlooked.

Coexistence of THRB and TBG gene mutations in a Turkish family

OBJECTIVE

Resistance to thyroid hormone is a syndrome characterized by high serum free T4 levels and unsuppressed serum TSH concentration. Thyroxine-binding globulin complete deficiency manifests with low serum total T4 and T3 levels and normal serum TSH concentration. Our objective is to describe a family with the coexistence of resistance to thyroid hormone and thyroxine-binding globulin complete deficiency.

METHODS

We conducted clinical studies and genetic analyses.

RESULTS

The proband presented with mental retardation, hearing loss, and recurrent upper respiratory tract infections accompanied by high serum levels of TSH, T3, T4, and high thyroglobulin antibody titers. His elder sister presented with normal TSH and T3 and high serum T4 levels. Both patients were found to be heterozygous for the mutation P453A in the thyroid hormone receptor beta (THRB) gene. One of the proband's brothers had low serum total T3 and T4 and normal TSH concentrations, without any clinical manifestations. He was hemizygous for the mutation P50fs51X in the TBG gene. The proband's mother showed slightly elevated TSH, normal total T3 and T4, and elevated titers of thyroperoxidase antibodies and thyroglobulin antibodies. She was heterozygous for both THRB and TBG genes mutations.

CONCLUSIONS

To our knowledge, this is the first report of the coexistence of THRB and TBG gene mutations in the same individual (mother of the proband), whereas other affected family members had only 1 of the 2 genes mutated. The case illustrates the difficulty that might be encountered in the interpretation of thyroid function tests when different genetic defects affecting thyroid function coexist.

Dichotomous responses to thyroid hormone treatment in a patient with primary hypothyroidism and thyroid hormone resistance

BACKGROUND

Resistance to thyroid hormone (RTH) is a rare syndrome of reduced TH sensitivity most often due to mutations affecting the β-isoform of the thyroid hormone receptor (TRβ). Patients with RTH may develop hypothyroidism as a result of surgery, mistreatment with radioiodine, or autoimmune thyroid disease.

PATIENT FINDINGS

We describe a patient who underwent partial thyroid lobectomy for benign goiter at age 17 and remained healthy through five uncomplicated pregnancies before abnormal laboratory results were noted. She was followed by multiple consecutive specialists after age 40, intermittently treated with levothyroxine, and referred to our clinic at age 66 because of severe progressive fatigue and abnormal thyroid function tests. Initial workup revealed elevated TH levels and inappropriately elevated thyroid-stimulating hormone. TH levels progressively declined into the normal range, accompanied by marked thyroid-stimulating hormone elevation. Antibody testing and thyroid biopsy confirmed Hashimoto's thyroiditis, and genetic testing revealed a TRβ mutation. Patient response to TH therapy has been good although limited by palpitations.

CONCLUSIONS

Patients with RTH may develop significant hypothyroidism with normal TH levels in the setting of Hashimoto's thyroiditis. RTH presents a unique challenge in both the diagnosis and management of autoimmune hypothyroidism.

Autoimmunity in patients with resistance to thyroid hormone

CONTEXT

Resistance to thyroid hormone (RTH) is an inherited syndrome most often caused by thyroid hormone receptor beta (TRbeta) gene mutations. Given that autoimmune thyroid disease (AITD) is prevalent in the general population, its coexistence with RTH has been presumed coincidental. It was recently proposed that chronic TSH stimulation in RTH may induce an autoimmune response, thereby increasing the chance of their coexistence.

OBJECTIVE

The aim was to examine the prevalence of AITD in a large cohort with RTH compared with their unaffected first-degree relatives.

SUBJECTS AND METHODS

Among 130 families, 330 individuals with RTH confirmed by the presence of TRbeta gene mutations and 92 unaffected first-degree relatives were tested for thyroglobulin and thyroperoxidase antibodies. The presence of AITD was based on at least one of the two antibodies being positive. Data were analyzed according to genotype, gender, age, and familial association. A large homogeneous family was analyzed separately.

RESULTS

Individuals with RTH had an increased likelihood of thyroid autoantibodies (odds ratio = 2.36; P = 0.002). In males, the odds of having AITD were higher in individuals with RTH compared to unaffected first-degree relatives (odds ratio = 2.91; P = 0.042). Although female subjects with RTH had an odds ratio of 1.95 for having thyroid autoantibodies, the difference was not statistically significant (P = 0.097). Antibody prevalence at different ages was not affected by genotype.

CONCLUSIONS

Individuals with RTH due to TRbeta gene mutations have an increased likelihood of AITD compared to unaffected relatives, but the prevalence of thyroid autoantibodies with advancing age is not affected by genotype. These novel findings demonstrate that the association between RTH and AITD is not coincidental.

Resistance to thyroid hormone in a patient with coexisting Graves' disease

BACKGROUND

Resistance to thyroid hormone (RTH) is a rare disorder in which an abnormality in the binding domain of the thyroid hormone receptor results in end-organ insensitivity to the actions of thyroid hormones. This disorder is sometimes misdiagnosed as Graves' disease due to the presence of a goiter with high Iodine-123 thyroid uptake and high levels of total and free thyroid hormones. Additionally, some patients with RTH may experience palpitations or tachycardia. There is a previous report of a patient with pituitary RTH and concurrent Graves' disease.

SUMMARY

We describe a patient who was found to have a goiter with signs and symptoms of hyperthyroidism by his primary care physician. Work-up revealed a low thyroid stimulating hormone (TSH), high thyroid-stimulating immunoglobulins, high Iodine-123 thyroid uptake, as well as increased homogenous activity in both thyroid glands on nuclear scan and a suppressed TSH. Diagnosis of Graves' disease was made, and the patient underwent radioactive ablation of the thyroid gland. The patient subsequently developed hypothyroidism and required a much higher dose of levothyroxine than his weight-based estimate of a full replacement dose to maintain euthyroidism. On 325 micog of daily levothyroxine the patient was clinically euthyroid and had a normal TSH although his levels of T3 and T4 were high. Work-up revealed a mutation in the thyroid hormone beta-receptor gene, consistent with diagnosis of RTH.

CONCLUSIONS

RTH is often misdiagnosed as Graves' disease. However, these disorders can coexist, and the concurrent presence of both disorders in a patient can present diagnostic challenges. A previous report of a patient with Graves' disease associated with RTH was published before gene sequencing could be used to confirm diagnosis of RTH. We present a patient with Graves' disease and concurrent RTH that was confirmed by gene sequencing, showing a mutation in the thyroid hormone receptor beta gene.

Clinical features of primary hyperthyroidism caused by Graves' disease admixed with resistance to thyroid hormone (P453T)

A 34-year-old Japanese woman was referred to the hospital because of general fatigue and palpitations. She was diagnosed as having resistance to thyroid hormone (RTH) and Hashimoto's thyroiditis at the age of 28. She felt general fatigue, palpitations, heat intolerance, and sweating for 6 months. Thyroid function tests demonstrated elevated levels of free triidothyronine (T3) and free thyroxine (T4) that were above detectable ranges and a completely suppressed level of TSH that was below the detectable range. Titers of anti-TSH receptor antibody (TRAb) and thyroid-stimulating antibody (TSAb) were positive. A 20-minute Technetium-m99 pertechnetate thyroid uptake imaging study showed an elevated value of 39.53% and a normal-shaped thyroid gland. These results indicated that Graves' disease (GD) caused primary hyperthyroidism. Pituitary and peripheral tissues responded to the presence of excess thyroid hormone in the patient. Oral administration of methimazole was started and continued for 1 year 10 months, after which it was ceased. Two years after the cessation of methimazole treatment, level of free T4 was elevated compared to reference range, but levels of TSH and free T3 were within normal reference ranges. Titers of TRAb and TSAb remained negative for 2 years. These findings indicated that the patient's GD was in remission. In conclusion, it is difficult to make a differential diagnosis between GD with RTH and GD alone if RTH is not diagnosed before the onset of GD. An antithyroid drug is able to cause the remission of GD with RTH.

Genotyping of resistance to thyroid hormone in South American population. Identification of seven novel missense mutations in the human thyroid hormone receptor beta gene

Thyroid Hormone Receptor beta (THRB) defects, typically transmitted as autosomal dominant traits, cause Resistance to Thyroid Hormone (RTH). We analyzed the THRB gene in thirteen South American patients with clinical evidence RTH from eleven unrelated families. Sequence analysis revealed seven novel missense mutations. Four novel mutations were identified in exon 9. The first, a c.991A>G transition which originates a substitution of asparagine by aspartic acid (p.N331D). The second nucleotide alteration consists of a guanine to cytosine transversion at position 1003 (c.1003G>C) and results in substitution of the alanine at codon 335 by proline (p.A335P). The third mutation, a c.1022T>C transition produces a change of leucine by proline (p.L341P). The fourth mutation detected in exon 9 was a c.1036C>T transition which replaces the leucine at codon 346 by phenylalanine (p.L346F). The sequencing of the exon 10 detected three novel missense mutations. The first, a c.1293A>G transition changing isoleucine 431 for methionine (p.I431M). The second, the cytosine at position 1339 was replaced by adenine (c.1339C>A) resulting in the replacement of proline by threonine (p.P447T). The third mutation detected in exon 10 was a c.1358C>T transition resulting in the substitution of proline at codon 453 by leucine (p.P453L). Finally, sequencing analysis of the THRB gene revealed three substitutions previously described (p.A268G, p.P453T and p.F459C). The p.P453T was found in two patients. In conclusion, we report thirteen patients with RTH caused by heterozygous mutations of the THRB gene. Seven of the identified mutations correspond to novel substitutions.

Thyroid hormone receptor beta gene mutation (P453A) in a family producing resistance to thyroid hormone

BACKGROUND

Resistance to thyroid hormone (RTH) is a dominantly inherited syndrome characterized by decreased responsiveness of target tissues to thyroid hormone. Two members of a Turkish family, a mother and son, had thyroid function tests suggestive of resistance to thyroid hormone (RTH).

METHODS

The clinical presentation was, however, different. The mother (proposita) had palpitation, weakness, tiredness, nervousness, dry mouth and was misdiagnosed as having multinodular toxic goiter which was treated with antithyroid drugs and partial thyroidectomy. Her younger son had attention deficit hyperactivity disorder and primary encopresis, but normal intellectual quotient. Both had elevated serum iodothyronine levels with nonsuppressed thyrotropin.

RESULTS

A mutation in one allele of the thyroid hormone receptor beta gene (P453A) was identified, providing a genetic confirmation for the diagnosis of RTH.

CONCLUSION

Mutational analysis of the TRss gene allows definitive diagnosis of RTH, potentially avoiding the need for protracted and expensive pituitary function testing.

Evaluation of thyroid hormone action in a case of generalized resistance to thyroid hormone with chronic thyroiditis: discovery of a novel heterozygous missense mutation (G347A)

Resistance to thyroid hormone (RTH) is a dominantly inherited syndrome of variable tissue hyporesponsiveness to thyroid hormone (TH). Its characteristics are a high level of TH and inappropriate lack of TSH suppression. RTH is mainly categorized as generalized RTH (GRTH), pituitary RTH (PRTH), and peripheral tissue RTH (PTRTH). Untreated subjects with GRTH usually achieve a normal metabolic state. We describe a 21-year-old Japanese woman with GRTH and coincidental chronic thyroiditis. Physical examination revealed palpable goiter, congenital alopecia on top of the head, and short stature. She showed elevated levels of free triiodothyronine (FT3) and free thyroxine (FT4), and an inappropriately normal level of TSH. Anti-thyroglobulin and anti-thyroid peroxidase antibodies were positive. A TRH stimulation test showed a normal TSH response. The patient received the standardized diagnostic protocol, administration of incremental doses of liothyronine (L-T3). The peak TSH level after the TRH stimulation test gradually decreased. The patient showed low sensitivity to TH in terms of bone metabolism, protein catabolism, lipid metabolism, and urine magnesium metabolism. Sequence analysis of the TR beta gene was performed with informed consent, and this revealed a novel heterozygous mutation at codon 347 resulting in a GGG (glycine) to GCG (alanine) substitution (G347A). The patient was diagnosed as having GRTH with chronic thyroiditis, and carrying a novel mutation, G347A, of the TR beta gene.

Proposing a causal link between thyroid hormone resistance and primary autoimmune hypothyroidism

Resistance to thyroid hormone (RTH) is a rare, inherited condition. It is characterised by raised circulating fT4 and TSH levels. The literature contains a number of descriptions of the finding of thyroid autoantibodies in patients with RTH. Until now, this has been attributed to the coincidental development of primary autoimmune thyroiditis as a second unrelated pathology. Our hypothesis is that the chronic TSH elevation in RTH stimulates lymphocytes to produce the pro-inflammatory cytokine TNF-alpha. TNF-alpha, in turn mediates thyroid cell destruction by binding to its receptors on thyrocytes, or indirectly by potentiating antibody formation or cytotoxic T lymphocyte production.