ESPE Abstracts

We introduce the ReTRIACt Trial (NCT05579327) of tiratricol (Triac) for MCT8-deficiency, a rare X-linked disease resulting from disordered thyroid hormone transport and characterized by profound neurodevelopmental delay and features of chronic peripheral thyrotoxicosis. The ReTRIACt Trial aims to verify the effects of tiratricol observed in previous studies. It is a double-blind, randomized, multicenter, placebo-controlled study to evaluate the effects of tiratricol discontinu...

Introduction: The European Registries for Rare Endocrine Conditions (EuRRECa) was created in collaboration with the European Reference Network on Rare Endocrine Conditions (Endo-ERN), the European Society for Paediatric Endocrinology and the European Society of Endocrinology to support the needs of the endocrine community.Aim: To describe the patient population and data entered in the EuRRECa Core Registry between June 2...

Thyroid hormone is crucial for metabolism and development. Cellular thyroid hormone homeostasis requires adequate function of (i) thyroid hormone transporter proteins, (ii) deiodinating enzymes and (iii) nuclear receptors. Thyroid hormone transporters are crucial for cellular uptake of T3 and T4. Over the last years, a number of thyroid hormone transporters have been identified and their physiological relevance has been established. The most well-studied example is MCT8 defici...

Introduction: The envelope protein of Human Endogenous Retrovirus type W (HERV-W-Env) has been shown to be associated with type 1 diabetes (T1D) pathogenesis in adults patients. This protein is expressed in pancreas of T1D patients and it seems to correlate with macrophage infiltrations. In vitro and in vivo studies have demonstrated that HERV-W-Env inhibits insulin secretion and promotes hyperglycemia. Furthermore, HERV could be implicated in other auto-immune disorders. The ...

Background: Mosaic Turner syndrome (TSM) commonly occurs in the form of 45,X/46,XX and 45,X/46,Xiq, although mosaicism including the presence of a Y chromosome has been well documented. It is associated with increased risk of gonadoblastoma (GB).Objective and hypotheses: To date, there are only six reported cases of TSM with a trisomy 18 karyotype, and only two of these were phenotypically female with 45,X, 47,XY+18 karyotype.Metho...

Background: Recently, T3 receptor alpha (TRα) mutations have been identified in a number of patients with varying degrees of growth impairment, delayed development, constipation, increases in serum T3 and decreases in T4 and rT3.Objective: To determine the spectrum of clinical and functional consequences of novel TRα mutations.Method: Clinical assessment and biochemical, imaging...

Background: EuRRECa (European Registries for Rare Endocrine Conditions) is a new project incorporating the development of a core endocrine registry and the development of an e-reporting programme for rare endocrine conditions (e-REC) that are covered within Endo-ERN (https://eurreca.net/e-rec/).Methods: 24 Endo-ERN centres within 12 countries participated in a pilot phase of e-REC...

Background: Registries are of key importance for a centre of expertise. Endo-ERN consists of 71 reference centres (RCs) that cover several groups of rare endocrine conditions within 8 themes (www.endo-ern.eu). It is unclear if awareness, participation and availability of registries is uniform for all conditions within Endo-ERN.Objective: To determine the extent of engagement in registries of Endo-ERN members.<p cl...

Introduction: Mutations in the thyroid hormone (TH) transporter MCT8 result in MCT8 deficiency, which is characterized by severe intellectual and motor disability and high serum T3 concentrations inducing thyrotoxicity in peripheral tissues. At present, no effective treatment is available, although preclinical studies suggest that the T3 analog Triac is a promising candidate to i) normalize serum T3 levels and thus alleviate the thyrotoxicosis and ii) restore TH signaling in t...

Background: Patients with a mutation in the thyroid hormone (TH) receptor TRα1 are characterized by growth retardation, delayed bone development, mild cognitive defects and constipation. They also have abnormal TH levels: low FT4, high T3, and low rT3 levels, suggesting an altered peripheral TH metabolism by deiodinases. The type 3 deiodinase (D3) inactivates TH by catalyzing the degradation of T3. D3 is importantly expressed in...