Endocrine Abstracts

Introduction: Patients with complex health care needs and severely limited communication and mobility may be less likely to participate in research studies, and may find continued participation in such studies challenging. Allan Herndon Dudley syndrome (AHDS), due to defective thyroid hormone transporter (MCT8), causes severe neurological and physical disability. A multicentre trial (the TRIAC trial) studying the efficacy of the thyroid hormone analogue TRIAC in this rare cond...

Introduction: Familial dysalbuminemic hyperthyroxinemia (FDH) is characterized by artefactual hyperthyroxinemia caused by enhanced binding affinity of thyroxine to the mutant albumin. However little is known about how FDH affects the measurement of thyroid hormones, especially FT3, across many assay platforms.Methods: Forty-eight genetically confirmed FDH patients (R218H mutation) had FT4 and FT3 measured with 1-step (ADVIA CENTAUR®, Siem...

Introduction: Isolated congenital central hypothyroidism (CeCH) is a rare entity associated with mutations in IGSF1, TSHB, TRHR, or the coding region of TBL1X. We describe a female with CeCH and extrathyroidal features due to a partial X-chromosomal deletion involving TBL1X and other genes. Further studies showed markedly reduced TBL1X expression in patient-derived leukocytes and enabled linkage of particular clinical phenotypes to ...

The UK newborn screening programme for congenital hypothyroidism (CH) facilitates prevention of neurodevelopmental delay in CH by enabling prompt diagnosis and treatment. Although the UK Newborn Screening Programme Centre (UKNSPC) defines a borderline bloodspot screening TSH (bsTSH) concentration as 10–20 mU/l, the lower cutoff used at Great Ormond Street Hospital (6 mU/l), enables diagnosis of true and transient CH in cases missed using UKNSPC criteria. We hypothesised t...

Background: Hyperthyroxinaemia with non-suppressed TSH, due to resistance to thyroid hormone (RTH) or TSH-secreting pituitary tumour (TSHoma), can be difficult to diagnose, particularly with coincident autoimmune thyroid disease (AITD).Methods: To determine presentation patterns of AITD coincident with RTH or TSHoma, we analysed our cohort of cases with dual diagnoses.Results: Nine patients with RTH had AITD. Six had Graves’ d...

The UK newborn screening programme for congenital hypothyroidism (CH) facilitates prevention of neurodevelopmental delay in CH by enabling prompt diagnosis and treatment. Although the UK Newborn Screening Programme Centre (UKNSPC) defines a borderline bloodspot screening TSH (bsTSH) concentration as 10–20 mU/l, the lower cutoff used at Great Ormond Street Hospital (6 mU/l), enables diagnosis of true and transient CH in cases missed using UKNSPC criteria. We hypothesised t...

Introduction: Thyroid function tests are frequently undertaken in children with non-specific symptoms suggestive of thyroid dysfunction. Infrequently, susceptibility of automated thyroid hormone assays to interference may generate misleading results, with the potential for inappropriate diagnosis and management. We report an unusual case with apparent subclinical hyperthyroidism, due to negative interference in particular TSH assay platforms, with an underlying genetic basis.<...

Background: Resistance to thyroid hormone (TH) beta (RTHβ), caused by mutations in THRB, is characterized by elevated serum (F)T4 accompanied by non-suppressed TSH concentrations. Disease features arise from variable resistance to TH action in tissues expressing Thyroid Hormone Receptor (TR) β (hypothalamus, pituitary, liver) and from thyrotoxic effects in tissues expressing TRα (heart, bone, brain). In symptomatic patients, treatment mainly involves be...

Background: Heightened awareness, as well as frequent thyroid function testing, have contributed to a recent rise in the incidence of thyrotropinomas. Microadenomas are now increasingly being recognized. The classical textbook description of thyrotropinomas is based on historically reported features in patients who typically had large/invasive lesions. The phenotype of microTSHomas could therefore differ.Methods: We reviewed the records of all TSHomas re...

Resistance to Thyroid Hormone alpha (RTHα) is characterised by tissue-selective hypothyroidism with near-normal thyroid function tests, and is due to thyroid receptor α gene mutations. We sought to correlate the clinical characteristics and response to thyroxine treatment of two RTHα patients with the properties of their defective TRα proteins.Clinical, biochemical and physiological parameters were assessed in each patient at baseline...