Congenital Hypothyroidism: A 2020-2021 Consensus Guidelines Update-An ENDO-European Reference Network Initiative Endorsed by the European Society for Pediatric Endocrinology and the European Society for Endocrinology

TSHR Variant Screening and Phenotype Analysis in 367 Chinese Patients With Congenital Hypothyroidism

Background

Genetic defects in the human thyroid-stimulating hormone (TSH) receptor (TSHR) gene can cause congenital hypothyroidism (CH). However, the biological functions and comprehensive genotype-phenotype relationships for most TSHR variants associated with CH remain unexplored. We aimed to identify TSHR variants in Chinese patients with CH, analyze the functions of the variants, and explore the relationships between TSHR genotypes and clinical phenotypes.

Methods

In total, 367 patients with CH were recruited for TSHR variant screening using whole-exome sequencing. The effects of the variants were evaluated by in-silico programs such as SIFT and polyphen2. Furthermore, these variants were transfected into 293T cells to detect their Gs/cyclic AMP and Gq/11 signaling activity.

Results

Among the 367 patients with CH, 17 TSHR variants, including three novel variants, were identified in 45 patients, and 18 patients carried biallelic TSHR variants. In vitro experiments showed that 10 variants were associated with Gs/cyclic AMP and Gq/11 signaling pathway impairment to varying degrees. Patients with TSHR biallelic variants had lower serum TSH levels and higher free triiodothyronine and thyroxine levels at diagnosis than those with DUOX2 biallelic variants.

Conclusions

We found a high frequency of TSHR variants in Chinese patients with CH (12.3%), and 4.9% of cases were caused by TSHR biallelic variants. Ten variants were identified as loss-of-function variants. The data suggest that the clinical phenotype of CH patients caused by TSHR biallelic variants is relatively mild. Our study expands the TSHR variant spectrum and provides further evidence for the elucidation of the genetic etiology of CH.

Hypopituitarism

Partial or complete deficiency of anterior or posterior pituitary hormone production leads to central hypoadrenalism, central hypothyroidism, hypogonadotropic hypogonadism, growth hormone deficiency, or arginine vasopressin deficiency depending on the hormones affected. Hypopituitarism is rare and likely to be underdiagnosed, with an unknown but rising incidence and prevalence. The most common cause is compressive growth or ablation of a pituitary or hypothalamic mass. Less common causes include genetic mutations, hypophysitis (especially in the context of cancer immunotherapy), infiltrative and infectious disease, and traumatic brain injury. Clinical features vary with timing of onset, cause, and number of pituitary axes disrupted. Diagnosis requires measurement of basal circulating hormone concentrations and confirmatory hormone stimulation testing as needed. Treatment is aimed at replacement of deficient hormones. Increased mortality might persist despite treatment, particularly in younger patients, females, and those with arginine vasopressin deficiency. Patients with complex diagnoses, pregnant patients, and adolescent pituitary-deficient patients transitioning to adulthood should ideally be managed at a pituitary tumour centre of excellence.

Polyethylene glycol thyroid-stimulating hormone (PEG-TSH) testing in the management of pediatric thyroid dysfunction

PURPOSE

The polyethylene glycol (PEG) methodology is used for investigating incongruities in laboratory assays, such as thyroid-stimulating hormone (TSH) measurements. The aim of the study is to investigate the practical application of PEG-TSH testing in cases of discrepancies between elevated TSH and normal free thyroxine (FT4) levels.

METHODS

A real-life observational study conducted in a tertiary medical center. The hospital's electronic database was queried for TSH tests performed in pediatric patients between 2015 and 2023. Of those, PEG-TSH were identified. Patients' clinical and biochemical characteristics and PEG-TSH-guided management were assessed.

RESULTS

In total, 2949 TSH tests were performed in 891 children and adolescents for various indications. Among them were 61 (2.1%) PEG-TSH results, mean age 7.1 ± 5.3 years, of 38 patients (4.3%), comprised of 16 with congenital hypothyroidism, 16 with subclinical hypothyroidism, and 6 with Hashimoto thyroiditis. Both the TSH and the PEG-TSH levels of patients with congenital hypothyroidism were higher than those of the other two groups (P = 0.021 and P = 0.009, respectively), with no group differences in FT4 levels. Spearman's correlation analysis revealed a strong association between TSH and PEG-TSH levels: r = 0.871, P < 0.001. In nearly one-half of the cases, clinical decisions made by clinicians (decreasing the dose or not initiating L-thyroxine treatment) were affected by the PEG-TSH results.

CONCLUSION

Our findings support PEG-TSH testing for determining appropriate TSH levels and avoid unnecessary thyroid hormone treatment among children and adolescents. We propose the suitability of managing their clinical condition based upon age-appropriate clinical parameters and FT4 levels when their PEG-TSH levels are within the normal range.

Endocrine, auxological and metabolic profile in children and adolescents with Down syndrome: from infancy to the first steps into adult life

Down syndrome (DS) is the most common chromosomal disorder worldwide. Along with intellectual disability, endocrine disorders represent a remarkable share of the morbidities experienced by children, adolescents and young adults with DS. Auxological parameters are plotted on syndrome-specific charts, as growth rates are reduced compared to healthy age- and gender-matched peers. Furthermore, children with DS are at increased risk for thyroid dysfunctions, diabetes mellitus, osteopenia and obesity compared to general population. Additionally, male individuals with DS often show infertility, while women tend to experience menopause at an overall younger age than healthy controls. Given the recent outstanding improvements in the care of severe DS-related comorbidities, infant mortality has dramatically decreased, with a current average life expectancy exceeding 60 years. Accordingly, the awareness of the specificities of DS in this field is pivotal to timely detect endocrine dysfunctions and to undertake a prompt dedicated treatment. Notably, best practices for the screening and monitoring of pediatric endocrine disorders in DS are still controversial. In addition, specific guidelines for the management of metabolic issues along the challenging period of transitioning from pediatric to adult health care are lacking. By performing a review of published literature, we highlighted the issues specifically involving children and adolescent with DS, aiming at providing clinicians with a detailed up-to-date overview of the endocrine, metabolic and auxological disorders in this selected population, with an additional focus on the management of patients in the critical phase of the transitioning from childhood to adult care.

De novo missense variants in exon 9 of SEPHS1 cause a neurodevelopmental condition with developmental delay, poor growth, hypotonia, and dysmorphic features

Selenophosphate synthetase (SEPHS) plays an essential role in selenium metabolism. Two mammalian SEPHS paralogues, SEPHS1 and SEPHS2, share high sequence identity and structural homology with SEPHS. Here, we report nine individuals from eight families with developmental delay, growth and feeding problems, hypotonia, and dysmorphic features, all with heterozygous missense variants in SEPHS1. Eight of these individuals had a recurrent variant at amino acid position 371 of SEPHS1 (p.Arg371Trp, p.Arg371Gln, and p.Arg371Gly); seven of these variants were known to be de novo. Structural modeling and biochemical assays were used to understand the effect of these variants on SEPHS1 function. We found that a variant at residue Trp352 results in local structural changes of the C-terminal region of SEPHS1 that decrease the overall thermal stability of the enzyme. In contrast, variants of a solvent-exposed residue Arg371 do not impact enzyme stability and folding but could modulate direct protein-protein interactions of SEPSH1 with cellular factors in promoting cell proliferation and development. In neuronal SH-SY5Y cells, we assessed the impact of SEPHS1 variants on cell proliferation and ROS production and investigated the mRNA expression levels of genes encoding stress-related selenoproteins. Our findings provided evidence that the identified SEPHS1 variants enhance cell proliferation by modulating ROS homeostasis. Our study supports the hypothesis that SEPHS1 plays a critical role during human development and provides a basis for further investigation into the molecular mechanisms employed by SEPHS1. Furthermore, our data suggest that variants in SEPHS1 are associated with a neurodevelopmental disorder.

Analysis of Serum Free Thyroxine Concentrations in Healthy Term Neonates Underlines Need for Local and Laboratory-Specific Reference Interval: A Systematic Review and Meta-Analysis of Individual Participant Data

Background: Initial evaluation of the hypothalamus-pituitary-thyroid axis is done by measuring serum free thyroxine (fT4) and thyrotropin concentrations. For correct interpretation of these measurements, reliable age-specific reference intervals (RIs) are fundamental. Since neonatal fT4 RIs conforming to the Clinical and Laboratory Standards Institute guidelines are not available for all assays, we set out to create literature-based uniform age-specific neonatal fT4 RIs that may be used for every assay. Methods: For meta-analysis of individual participant fT4 concentrations, we systematically searched MEDLINE and Embase (search date December 6, 2023; PROSPERO registration CRD42016041871). We searched for studies reporting fT4 concentrations in healthy term newborns aged 2-27 days, born to mothers without thyroid disease in iodine-sufficient regions. Authors were invited to supply data. Due to standardization differences between assays, data could not be combined for meta-analysis directly, and we attempted to normalize the data using two distinct methods. Results: We obtained 4206 fT4 concentrations from 20 studies that used 13 different assays from 6 manufacturers. First, we set out to normalize fT4 data using the mean and standard deviation of (assay-specific) adult RIs. fT4 concentrations were transformed into Z-scores, assuming a normal distribution. Using a linear mixed-effects model (LMM), we still found a significant difference between fT4 concentration across studies (p < 0.001), after this normalization. As a second approach, we normalized the fT4 concentrations using data from a method/assay comparison study. We used the relationship between the Cobas assay and the other assays as a reference point to convert all values to Cobas values. However, this method also failed to produce consistent results, with significant differences between the normalized data (LMM p < 0.001). Conclusions: We conclude that our attempts at normalizing fT4 assay results were unsuccessful. Confounders related to our unsuccessful analysis may be assay related and/or biological. These findings have significant implications for patient care, since relying on RIs from literature may result in erroneous interpretation of results. Therefore, we strongly recommend to establish local RIs for accurate interpretation of serum fT4 concentrations in neonates.

Hypothyroxinemia and weight velocity in preterm infants

OBJECTIVES

Hypothyroxinemia of prematurity (HOP) is characterized by low free thyroxine (FT4) associated with low or normal thyroid stimulating hormone (TSH). The objective of this study is to define FT4 and TSH values in very preterm infants (<32 weeks postmenstrual age, PMA) and correlate hypothyroxinemia and levothyroxine treatment with growth velocity at 28 days and 36 weeks PMA.

METHODS

Preterm neonates <32 weeks PMA admitted to the regional neonatal intensive care unit (NICU) at the Children's Hospital of Georgia (USA) between January 2010 and July 2022 were routinely screened for hypothyroxinemia. FT4 and TSH values were obtained on 589 eligible neonates between day of life (DOL) 4 and 14. Growth velocity (g/kg/day) from DOL 14 to DOL 28 and 36-weeks PMA were calculated for each neonate and potential explanatory variables (PMA, sex, and race) were incorporated into multivariate regression models to identify associations between HOP and growth velocity.

RESULTS

In 589 preterm infants, PMA at birth was strongly associated inversely with FT4 (R=0.5845) and modestly with TSH (R=0.2740). Both FT4 and gestational age, but not TSH or levothyroxine treatment, were associated with growth velocity at 28 days of life and at 36 weeks PMA.

CONCLUSIONS

We provide a large data set for identifying FT4 and TSH measurements and identify hypothyroxinemia of prematurity as a potential mediator of slow postnatal growth in very preterm infants.

[Inequalities in time to diagnosis of Down Syndrome in Bolivia]

Down Syndrome is the most common genetic condition and a leading cause of intellectual disability. Individuals in rural areas, particularly those with disabilities, often face disparities in healthcare access. Analyzing clinical records of patients diagnosed with Down Syndrome between 2013 and 2022 by the Institute of Genetics at the Universidad Mayor de San Andrés in La Paz, Bolivia, this study examined the time to diagnosis for 250 patients with Down Syndrome. The findings revealed that patients from rural areas with Down Syndrome take an average of five months to receive a diagnosis, compared to two months in urban areas (p<0.001). No significant differences were found in the time to diagnosis based on gender. However, a higher proportion of males from rural areas was observed (p=0.03). The results suggest that individuals in rural areas face challenges in receiving a timely diagnosis. On the other hand, women may not be brought to cities for proper diagnosis and treatment due to gender biases in certain communities. The importance of improving access to early diagnosis and treatment in rural areas is emphasized.

PD-1/PD-L1 Inhibitor - Related Adverse Events and Their Management in Breast Cancer

As the positive results of multiple clinical trials were released, the Programmed cell death 1 (PD-1) and Programmed cell death ligand 1 (PD-L1) inhibitors emerge as the focus of integrative breast cancer treatment. PD-1/PD-L1 inhibitors are often used as a sequential agent to be combined with other agents such as chemotherapeutic agents, targeted agents, and radiation therapy. As multiple therapies are administered simultaneously or in sequence, they are prone to a variety of adverse effects on patients while achieving efficacy. It is a challenge for clinicians to maintaining the balance between immune-related adverse effects(irAEs) and treatment efficacy. Previous literatures have paid lots of attention on the adverse effects caused by immunosuppressive agents themselves, while there is a dearth of the research on the management of adverse immune effects during the combination of immunotherapy with other treatments. In this review, we discuss the overall incidence of irAEs caused by PD-1/PD-L1 inhibitors in combination with various types of treatments in breast cancer, including chemotherapy, CTLA-4 inhibitors, targeted therapy, and radiotherapy, and systematically summarizes the clinical management to each organ-related adverse immune reaction. It is important to emphasize that in the event of irAEs such as neurological, hematologic, and cardiac toxicity, there is no alternative treatment but to terminate immunotherapy. Thus, seeking more effective strategy of irAEs' management is imminent and clinicians are urged to raise the awareness of the management of adverse immune reactions.

JAG1 Variants Confer Genetic Susceptibility to Thyroid Dysgenesis and Thyroid Dyshormonogenesis in 813 Congenital Hypothyroidism in China

Background and Objective

Congenital hypothyroidism (CH) is indeed a prevalent neonatal endocrine disorder, affecting approximately 1 in 2000-3000 newborns worldwide, and 1 in 2400 newborns in China. Despite its high incidence, the genetic causes of CH, particularly those related to thyroid dysgenesis (TD), are still not well understood. However, previous studies have suggested that JAG1 may be a potential susceptibility gene for congenital thyroid defects. To explore the association between JAG1 and CH, we screened JAG1 variants in a large cohort of 813 CH patients.

Methods

We performed genetic analysis of JAG1 using next-generation sequencing in 813 CH cases. The pathogenicity of the variants was assessed by bioinformatics softwares, protein sequence conservation analysis, and hydrophobic analysis. Further genetic analysis was conducted targeting 20 CH-related genes in these 25 JAG1 variant carriers.

Results

We identified 10 pathogenic missense mutations (p.V45L, p.V272I, p.P552L, p.G610E, p.G852D, p.A891T, p.E1030K, p.R1060W, p.A1131T, p.P1174L) carried by 25 patients, the mutation rate of JAG1 in CH was 3.08%. Among these 25 patients, 16 with 1 variant, 6 with 2 variants, and the other 3 with 3 variants. Our findings indicated that JAG1 variants confer genetic susceptibility to both TD and DH, but with different inheritance models. JAG1 variants lead to TD mainly through monogenic model, while for DH cases, both monogenic mechanisms and oligogenic mechanisms play a pivotal role. Oligogenicity may contribute to the disease severity of DH.

Conclusion

JAG1 is a shared genetic factor in TD and DH, with a detection rate of 3.08% in Chinese individuals with CH. A comparison between the oligogenic and monogenic groups suggests a gene dosage effect in CH. Patients with the same JAG1 mutation exhibit diverse clinical phenotypes, indicating complex mechanisms underlying phenotypic heterogeneity.

Screening for Delayed Thyroid Stimulation Hormone Rise and Atypical Congenital Hypothyroidism in Infants Born Very Preterm and Infants with Very Low Birth Weight

OBJECTIVE

To determine among infants born very preterm (VPT) or with very low birth weight (VLBW) the incidence of alterations in thyroid function and associated comorbidities; the incidence of atypical congenital hypothyroidism (CH) requiring thyroxine therapy; and reference ranges for rescreening at 1 month of age.

STUDY DESIGN

A retrospective review of infants born VPT or with VLBW and admitted to UC Irvine Medical Center between January 1, 2012, and December 31, 2020. Repeat thyroid screening was obtained at 1 month of life (+10 days). Infants with thyroid-stimulating hormone (TSH) >5 μIU/mL or free thyroxine <0.8 ng/dL underwent follow-up testing and endocrinology consultation. Initial newborn screening (NBS) and repeat thyroid screening data were collected via chart review. Demographic data and short-term outcomes were abstracted from the California Perinatal Quality Care Collaborative database.

RESULTS

In total, 430 patients were included; 64 of 429 patients (14.9%) had TSH >5 μIU/mL and 20 of 421 patients (4.8%) had free thyroxine <0.8 ng/dL. Logistic regression analysis identified small for gestational age (P = .044), patent ductus arteriosus (P = .013), and late-onset sepsis (P = .026) as risk factors associated with delayed TSH rise. Atypical CH requiring treatment through neonatal intensive care unit discharge was diagnosed in 6 patients (incidence of 1.4%); none were identified by NBS. The 90th percentile TSH for infants with extremely low birth weight (<1000 g) was 7.2 μIU/mL, and the 95th percentile for those with birth weight of 1000-1500 g was 6.1 μIU/mL; using these cutoff values identified all infants diagnosed with atypical CH with 100% sensitivity and 90%-95% specificity.

CONCLUSIONS

Abnormal thyroid function is common in infants born preterm. Those infants, including some with atypical CH, are missed by NBS. We recommend repeat thyroid screening with TSH at 1 month of age in infants born VPT or infants with VLBW to identify CH that may require therapy.

History of Neonatal Screening of Congenital Hypothyroidism in Portugal

Congenital hypothyroidism (CH) leads to growth and development delays and is preventable with early treatment. Neonatal screening for CH was initiated in Portugal in 1981. This study examines the history of CH screening in the country. Data were obtained from annual reports and from the national database of neonatal screening laboratory. The CH screening strategy primarily relies on the thyroid-stimulating hormone (TSH), followed by total thyroxine measurement as the second tier for confirmation. The TSH cutoff started at 90 mIU/L, decreasing to the actual 10 mIU/L. The coverage of the screening program has increased rapidly; although voluntary, it reached about 90% in 6 years and became universal in 10 years. Guideline and cutoff updates led to the identification of over 200 additional cases, resulting in specific retesting protocols for preterm and very-low-birth-weight babies. The actual decision tree considers CH when TSH levels are above 40 mIU/L. Data from the CH screening also provide an indication of the iodine status of the population, which is presently indicative of iodine insufficiency. The Portuguese neonatal screening for CH is a history of success. It has rapidly and continuously adapted to changes in knowledge and has become a universal voluntary practice within a few years.

Transition from pediatric to adult care in patients with Turner syndrome in Italy: a consensus statement by the TRAMITI project

PURPOSE

Transition from pediatric to adult care is associated with significant challenges in patients with Turner syndrome (TS). The objective of the TRansition Age Management In Turner syndrome in Italy (TRAMITI) project was to improve the care provided to patients with TS by harnessing the knowledge and expertise of various Italian centers through a Delphi-like consensus process.

METHODS

A panel of 15 physicians and 1 psychologist discussed 4 key domains: transition and referral, sexual and bone health and oncological risks, social and psychological aspects and systemic and metabolic disorders.

RESULTS

A total of 41 consensus statements were drafted. The transition from pediatric to adult care is a critical period for patients with TS, necessitating tailored approaches and early disclosure of the diagnosis to promote self-reliance and healthcare autonomy. Fertility preservation and bone health strategies are recommended to mitigate long-term complications, and psychiatric evaluations are recommended to address the increased prevalence of anxiety and depression. The consensus also addresses the heightened risk of metabolic, cardiovascular and autoimmune disorders in patients with TS; regular screenings and interventions are advised to manage these conditions effectively. In addition, cardiac abnormalities, including aortic dissections, require regular monitoring and early surgical intervention if certain criteria are met.

CONCLUSIONS

The TRAMITI consensus statement provides valuable insights and evidence-based recommendations to guide healthcare practitioners in delivering comprehensive and patient-centered care for patients with TS. By addressing the complex medical and psychosocial aspects of the condition, this consensus aims to enhance TS management and improve the overall well-being and long-term outcomes of these individuals.

Promoting Choosing Wisely Thyroid Function Test Guidelines in a Large Pediatric Hospital System

BACKGROUND

Free thyroxine (fT4) is often ordered when not indicated. The goal of the current study was to use quality improvement tools to identify and implement an optimal approach to reduce inappropriate fT4 testing throughout a large pediatric hospital system.

METHODS

After reviewing evidence-based guidelines and best practices, a thyroid-stimulating hormone with reflex to fT4 test and an outpatient thyroid order panel with clinical decision support at order entry, along with several rounds of provider education and feedback, were implemented. Outpatient and inpatient order sets and system preference lists were reviewed with subject matter experts and revised when appropriate. Tracking metrics were identified. Automated monthly run charts and statistical process control charts were created using data retrieved from the electronic health record. Charts established baseline data, balancing measure data, monitored the impact of interventions, and identified future interventions.

RESULTS

Over a 44-month period, among nonendocrinology providers, a reduction in fT4 and thyroid-stimulating hormone co-orders from 67% to 15% and an increase in reflex fT4 tests from 0% to 77% was obtained in inpatient and outpatient settings. Direct cost savings as a result of performing 5179 fewer fT4 tests over 3 years was determined to be $45 800.

CONCLUSIONS

After implementation of a reflex fT4 test, a novel order panel with clinical decision support, provider education, and changes to ordering modes, a large and sustainable reduction in fT4 tests that was associated with significant cost savings was achieved among nonendocrinology providers.

A literature review on the redundancy of additional thyroid function tests in neonates of mothers with hypothyroidism

AIM

Newborn thyroid screening tests are carried out during the first days after birth in many parts of the world. The aim of this review was to assess whether additional thyroid function tests of neonates born to mothers with hypothyroidism are necessary to diagnose newborns with congenital hypothyroidism (CH) missed by the usual screening test.

METHODS

A search in PubMed and Google Scholar databases was conducted for pertinent studies, using relevant keywords. All studies that were published in any language from 1 January 2000 to 30 June 2023 were included. Observational cohort studies were included in the analysis, while case reports and studies not referring to neonates were excluded.

RESULTS

Thirteen studies were identified comprising more than 4400 infants with CH. Studies with the larger study populations recommended against additional testing in healthy infants of hypothyroid mothers. Similar were the results of some smaller retrospective studies. Few studies identified in total 16 infants with CH that were missed on neonatal screening without, though, a definite causative link between the mother's and the infant's thyroid dysfunction.

CONCLUSION

Based on available data, additional thyroid function tests seem redundant in identifying undiagnosed cases of CH. Larger studies are needed to reach a definite conclusion.

The Quartile Levels of Thyroid-Stimulating Hormone by Newborn Screening Stratified Risks of Neurodevelopmental Impairment in Extremely Preterm Infants - A Population Cohort Study

BACKGROUND

To evaluate whether thyroid-stimulating hormone (TSH) by newborn screening (NBS) at birth and at discharge can be surrogate markers for neurodevelopmental impairment (NDI) in extremely preterm infants.

METHODS

The population cohort enrolled infants born <29 weeks' gestation in 2008 - 2020 in southern Taiwan. Infants with a maternal history of thyroid disorders and infants who required thyroxine supplementation during hospitalization were excluded. TSH levels by NBS at birth and at term-equivalent age (TEA)/discharge were respectively categorized into the lowest quartile, the interquartile range, and the highest quartile, which were correlated to NDI outcomes.

RESULTS

Among 392 patients with paired TSH data, 358 (91%) were prospectively followed until corrected age 24 months. At birth, infants with lowest-quartile TSH had higher NDI risks (OR 2.3, 95% CI 1.3 - 4.1, P = 0.004) compared to infants with interquartile-range TSH. Conversely, by TEA/discharge, infants with highest-quartile TSH had increased NDI (OR 1.9, 1.0 - 3.4, P = 0.03). By paired TSH categories, infants persistently in the lowest TSH quartile (48%, aOR 4.4, 1.4 - 14.5, P = 0.01) and those with a shift from interquartile range to the highest quartile (32%, aOR 2.7, 1.0 - 7.4, P = 0.046) had increased NDI risks compared with the reference with consistent interquartile-range TSH.

CONCLUSIONS

Extremely preterm infants persistently in the lowest-quartile TSH level at birth and at discharge had the highest NDI risk. TSH quartile levels by NBS may serve as a population surrogate biomarker for assessing NDI risks in infants born extremely preterm.

Diagnosing and treating anterior pituitary hormone deficiency in pediatric patients

Hypopituitarism, or the failure to secrete hormones produced by the anterior pituitary (adenohypophysis) and/or to release hormones from the posterior pituitary (neurohypophysis), can be congenital or acquired. When more than one pituitary hormone axis is impaired, the condition is known as combined pituitary hormone deficiency (CPHD). The deficiency may be primarily due to a hypothalamic or to a pituitary disorder, or concomitantly both, and has a negative impact on target organ function. This review focuses on the pathophysiology, diagnosis and management of anterior pituitary hormone deficiency in the pediatric age. Congenital hypopituitarism is generally due to genetic disorders and requires early medical attention. Exposure to toxicants or intrauterine infections should also be considered as potential etiologies. The molecular mechanisms underlying the fetal development of the hypothalamus and the pituitary are well characterized, and variants in the genes involved therein may explain the pathophysiology of congenital hypopituitarism: mutations in the genes expressed in the earliest stages are usually associated with syndromic forms whereas variants in genes involved in later stages of pituitary development result in non-syndromic forms with more specific hormone deficiencies. Tumors or lesions of the (peri)sellar region, cranial radiation therapy, traumatic brain injury and, more rarely, other inflammatory or infectious lesions represent the etiologies of acquired hypopituitarism. Hormone replacement is the general strategy, with critical periods of postnatal life requiring specific attention.

Comparison between transient and permanent congenital hypothyroidism on a thyroid function test after re-evaluation

PURPOSE

Congenital hypothyroidism (CH) is diagnosed with neonatal screening and is treated early in the neonatal period. Among these patients, transient CH (TCH) is included and requires re-evaluation. The purpose of this study was to find the best way to discontinue levothyroxine and to find trends in thyroid function tests (TFTs) after re-evaluation.

METHODS

We retrospectively reviewed 388 patients diagnosed with CH. They were classified as permanent CH (PCH) and TCH. The total number of the PCH and TCH groups was 83 (51 boys and 32 girls). We compared clinical parameters to predict TCH and to identify the trends of TFT.

RESULTS

The first thyroid-stimulating hormone (TSH) value after discontinuation and the average TSH value for 1, 2, and 3 years were all significantly higher in the PCH group (P<0.01). The first fT4 value after discontinuation and the average fT4 value for 1, 2, and 3 years were all significantly higher in the TCH group (P<0.01). The optimal cutoff value on the receiver operating characteristic curve for PCH prediction with an average of 3 years of TSH was greater than 9.05 μIU/mL, which was predicted with a sensitivity of 100% and a specificity of 100%.

CONCLUSION

When the TSH value ranges from 10 μIU/mL to 20 μIU/mL, clinicians can discontinue levothyroxine if the next result is around 10 μIU/mL or shows a decreasing trend.

[Disruptors of thyroid hormones: Which consequences for human health and environment?]

Endocrine disruptors (EDs) of chemical origin are the subject of numerous studies, some of which have led to measures aimed at limiting their use and their impact on the environment and human health. Dozens of hormones have been described and are common to all vertebrates (some chemically related messengers have also been identified in invertebrates), with variable roles that are not always known. The effects of endocrine disruptors therefore potentially concern all animal species via all endocrine axes. These effects are added to the other parameters of the exposome, leading to strong, multiple and complex adaptive pressures. The effects of EDs on reproductive and thyroid pathways have been among the most extensively studied over the last 30 years, in a large number of species. The study of the effects of EDs on thyroid pathways and brain development goes hand in hand with increasing knowledge of 1) the different roles of thyroid hormones at cellular or tissue level (particularly developing brain tissue) in many species, 2) other hormonal pathways and 3) epigenetic interactions. If we want to understand how EDs affect living organisms, we need to integrate results from complementary scientific fields within an integrated, multi-model approach (the so-called translational approach). In the present review article, we aim at reporting recent discoveries and discuss prospects for action in the fields of medicine and research. We also want to highlight the need for an integrated, multi-disciplinary approach to studying impacts and taking appropriate action.

Comorbidity in Congenital Hypothyroidism-A Nationwide, Population-based Cohort Study

CONTEXT

Patients with congenital hypothyroidism (CH) are affected more often than the general population by other chronic diseases and neurological difficulties.

OBJECTIVE

The aim of this nationwide population-based register study was to investigate the incidence of congenital malformations, comorbidities, and the use of prescribed drugs in patients with primary CH.

METHODS

The study cohort and matched controls were identified from national population-based registers in Finland. All diagnoses from birth until the end of 2018 were collected from the Care Register, and subject-specific prescription drug purchases were identified from The Prescription Register from birth until the end of 2017.

RESULTS

Diagnoses of neonatal and chronic diseases were collected for 438 full-term patients and 835 controls (median follow-up time 11.6 years; range, 0-23 years). Newborns with CH were more often found to have neonatal jaundice (11.2% and 2.0%; P < .001), hypoglycemia (8.9% and 2.8%; P < .001), metabolic acidemia (3.2% and 1.1%; P = .007), and respiratory distress (3.9% and 1.3%; P < .003) as compared to their matched controls.Congenital malformations were diagnosed in 66 of 438 (15.1%) CH patients and in 62 of 835 (7.4%) controls (P < .001). The most commonly affected extrathyroidal systems were the circulatory and musculoskeletal systems. The cumulative incidence of hearing loss and specific developmental disorders was higher among CH patients than controls. The use of antidepressant and antipsychotic drugs was similar in CH patients and their controls.

CONCLUSION

CH patients have more neonatal morbidity and congenital malformations than their matched controls. The cumulative incidence of neurological disorders is higher in CH patients. However, our results do not support the existence of severe psychiatric comorbidity.

Cerebral Cortical Thickness Morphometry and Neurocognitive Correlations in Adolescents With Congenital Hypothyroidism

CONTEXT

Subtle cognitive impairments have been described in children with congenital hypothyroidism (CH) detected by neonatal screening (NS), even with early and adequate treatment. Patients with CH may present with brain cortical thickness (CT) abnormalities, which may be associated with neurocognitive impairments.

OBJECTIVE

This work aimed to evaluate the CT in adolescents with CH detected by the NS Program (Paraná, Brazil), and to correlate possible abnormalities with cognitive level and variables of neurocognitive prognosis.

METHODS

A review was conducted of medical records followed by psychometric evaluation of adolescents with CH. Brain magnetic resonance imaging with analysis of 33 brain areas of each hemisphere was performed in 41 patients (29 girls) and in a control group of 20 healthy adolescents. CT values were correlated with Full-scale Intelligence Quotient (FSIQ) scores, age at start of treatment, pretreatment thyroxine levels, and maternal schooling.

RESULTS

No significant difference in CT between patients and controls were found. However, there was a trend toward thinning in the right lateral orbitofrontal cortex among patients and in the right postcentral gyrus cortex among controls. CT correlated significantly with FSIQ scores and with age at start of treatment in 1 area, and with hypothyroidism severity in 5 brain areas. Maternal schooling level did not correlate with CT but was significantly correlated with FSIQ. Cognitive level was within average in 44.7% of patients (13.2% had intellectual deficiency).

CONCLUSION

There was a trend toward morphometric alterations in the cerebral cortex of adolescents with CH compared with healthy controls. The correlations between CT and variables of neurocognitive prognosis emphasize the influence of hypothyroidism on cortical development. Socioeconomic status exerts a limiting factor on cognitive outcome.

Neurovascular unit disruption and blood-brain barrier leakage in MCT8 deficiency

BACKGROUND

The monocarboxylate transporter 8 (MCT8) plays a vital role in maintaining brain thyroid hormone homeostasis. This transmembrane transporter is expressed at the brain barriers, as the blood-brain barrier (BBB), and in neural cells, being the sole known thyroid hormone-specific transporter to date. Inactivating mutations in the MCT8 gene (SLC16A2) cause the Allan-Herndon-Dudley Syndrome (AHDS) or MCT8 deficiency, a rare X-linked disease characterized by delayed neurodevelopment and severe psychomotor disorders. The underlying pathophysiological mechanisms of AHDS remain unclear, and no effective treatments are available for the neurological symptoms of the disease.

METHODS

Neurovascular unit ultrastructure was studied by means of transmission electron microscopy. BBB permeability and integrity were evaluated by immunohistochemistry, non-permeable dye infiltration assays and histological staining techniques. Brain blood-vessel density was evaluated by immunofluorescence and magnetic resonance angiography. Finally, angiogenic-related factors expression was evaluated by qRT-PCR. The studies were carried out both in an MCT8 deficient subject and Mct8/Dio2KO mice, an AHDS murine model, and their respective controls.

RESULTS

Ultrastructural analysis of the BBB of Mct8/Dio2KO mice revealed significant alterations in neurovascular unit integrity and increased transcytotic flux. We also found functional alterations in the BBB permeability, as shown by an increased presence of peripheral IgG, Sodium Fluorescein and Evans Blue, along with increased brain microhemorrhages. We also observed alterations in the angiogenic process, with reduced blood vessel density in adult mice brain and altered expression of angiogenesis-related factors during brain development. Similarly, AHDS human brain samples showed increased BBB permeability to IgG and decreased blood vessel density.

CONCLUSIONS

These findings identify for the first time neurovascular alterations in the MCT8-deficient brain, including a disruption of the integrity of the BBB and alterations in the neurovascular unit ultrastructure as a new pathophysiological mechanism for AHDS. These results open a new field for potential therapeutic targets for the neurological symptoms of these patients and unveils magnetic resonance angiography as a new non-invasive in vivo technique for evaluating the progression of the disease.

[Evaluation and optimization of newborn screening by structured long-term follow-up-using the example of inherited metabolic diseases]

Newborn screening (NBS) is a highly successful secondary prevention program with the goal of preventing severe sequelae of congenital, mostly genetic, diseases by identifying them as early as possible, ideally in the pre-symptomatic period. Studies to date have shown the important achievements of NBS programs but also reveal a number of relevant weaknesses. These include the often incompletely understood natural history and phenotypic diversity of rare diseases as well as the inadequate ability to accurately predict individual disease severity at an early stage and thus the uncertainties in case definition, risk stratification, and treatment indication.In light of the rapid developments in high-throughput genetic technologies and the associated opportunities for substantial future expansion of NBS programs, it seems overdue to make structured long-term follow-up and the subsequent evaluation of the long-term health benefits mandatory for individuals with rare diseases identified through NBS. This article explains the importance of long-term follow-up for the evaluation and continuous optimization of the screening. Long-term clinical outcomes of people with inherited metabolic diseases identified by NBS are presented as examples.

Allan-Herndon-Dudley syndrome in Hong Kong: Implication for newborn screening

BACKGROUND

Allan-Herndon-Dudley syndrome (MCT 8 deficiency) is an X-linked recessive condition caused by hemizygous pathogenic variants in SLC16A2 encoding the monocarboxylate transporter 8 (MCT8). Patients present with global developmental delay and neurological impairment, and abnormal serum thyroid function tests. The drug, 3,3',5 triiodothyroacetic acid (TRIAC), was recently demonstrated to improve the endocrinological profile. Improvement in diagnostic approach is key to earlier start of treatment.

PATIENT FINDINGS

We described four Chinese patients with MCT8 deficiency undergoing different diagnostic odysseys. Their initial presentation included global developmental delay and dystonia. Patient 2 also had epilepsy. Patients 1 and 2 presented with two novel variants: (1)hemizygous NM_006517.4(SLC16A2):c.1170 + 2 T > A; p.(?), and (2)hemizygous NM_006517.4(SLC16A2):c.305dupT; p.(Val103GlyfsTer17) respectively. Patients 3 and 4 were biological brothers harboring hemizygous NM_006517.4(SLC16A2):c.305dupT; p.(Val103GlyfsTer17), which was first reported in 2004. We obtained the measurement of triiodothyronine (T3) and reverse T3 (rT3) from dried blood spot samples collected on Day 1 of life from Patient 1 and studied the biomarkers (rT3 and T3/rT3 ratio) proposed by Iwayama et al. for the detection of MCT8 deficiency at birth. Our data verified the significantly reduced rT3 level in Patient 1, compared with healthy newborns, although low T3 level and comparable T3/rT3 ratio with controls were detected.

SUMMARY

Patients with MCT8 deficiency often undergo diagnostic odysseys. An early diagnosis could be missed by a normal newborn thyroid function screening result based on biochemical measurement of TSH and/or T4/fT4. Early detection of rT3 is key to improving current diagnostic approach.

CONCLUSION

We recommend that full thyroid function profile (TSH, T4/fT4, T3/fT3, rT3) be considered early for all pediatric patients presenting with unexplained developmental delay and/or dystonia. The potential inclusion of rT3 measurement in newborn screening may prove promising.

Borealin/CDCA8 deficiency alters thyroid development and results in papillary tumor-like structures

Background

BOREALIN/CDCA8 mutations are associated with congenital hypothyroidism and thyroid dysgenesis. Borealin is involved in mitosis as part of the Chromosomal Passenger Complex. Although BOREALIN mutations decrease thyrocyte adhesion and migration, little is known about the specific role of Borealin in the thyroid.

Methods

We characterized thyroid development and function in Borealin-deficient (Borealin +/-) mice using histology, transcriptomic analysis, and quantitative PCR.

Results

Thyroid development was impaired with a hyperplastic anlage on embryonic day E9.5 followed by thyroid hypoplasia from E11.5 onward. Adult Borealin +/- mice exhibited euthyroid goiter and defect in thyroid hormone synthesis. Borealin +/- aged mice had disorganized follicles and papillary-like structures in thyroids due to ERK pathway activation and a strong increase of Braf-like genes described by The Cancer Genome Atlas (TCGA) network of papillary thyroid carcinoma. Moreover, Borealin +/- thyroids exhibited structural and transcriptomic similarities with papillary thyroid carcinoma tissue from a human patient harboring a BOREALIN mutation, suggesting a role in thyroid tumor susceptibility.

Conclusion

These findings demonstrate Borealin involvement in critical steps of thyroid structural development and function throughout life. They support a role for Borealin in thyroid dysgenesis with congenital hypothyroidism. Close monitoring for thyroid cancer seems warranted in patients carrying BOREALIN mutations.

Two Cases of Congenital Hypothyroidism Revealing Thyroid Agenesis

Congenital hypothyroidism (CH) may have major detrimental effects on growth and neurological development, but early intervention leads to excellent outcomes. CH is classified as transient or permanent, primary or secondary, with primary CH being the most common neonatal endocrine disorder. Most patients with CH do not present any typical signs and symptoms of hypothyroidism shortly after birth, partly due to transplacental maternal thyroid hormone transfer and residual neonatal thyroid function. This paper reports on two CH cases. During the initial Neonatal Intensive Care Unit (NICU) admission phase, CH was not suspected due to nonspecific signs. The distinct characteristics of our cases are as follows: both infants were admitted to the NICU for respiratory distress syndrome, requiring invasive mechanical ventilation, and both were born to diabetic mothers. Following extubation, they both showed similar neurological issues, including reduced muscle tone and feeding difficulties. Initially, those symptoms were attributed to delayed clearance of analgesic and sedative medication. However, symptoms progressively worsened over time. Subsequent tests revealed both meeting CH diagnostic criteria: an unusual ultrasound indicating thyroid agenesis and abnormal hormone levels. Guided by the pediatric endocrinology team, prompt hormonal treatment was started with improvements in neurocognitive function and feeding. Usually, CH screening involves blood samples from healthy newborns at 2-3 days of life. Abnormal results require confirmation, prompting treatment within two weeks. Certain NICU-admitted infants face higher diagnosis delays, as seen in those two cases where CH screening was postponed. Thus, for all neonates with persistent pathologies unresponsive to standard etiological treatment, conducting a comprehensive anamnestic evaluation of the medical history, along with maternal preconceptional and prenatal nutrition, is recommended.

Perinatal asphyxia and hypothermic treatment from the endocrine perspective

Introduction

Perinatal asphyxia is one of the three most important causes of neonatal mortality and morbidity. Therapeutic hypothermia represents the standard treatment for infants with moderate-severe perinatal asphyxia, resulting in reduction in the mortality and major neurodevelopmental disability. So far, data in the literature focusing on the endocrine aspects of both asphyxia and hypothermia treatment at birth are scanty, and many aspects are still debated. Aim of this narrative review is to summarize the current knowledge regarding the short- and long-term effects of perinatal asphyxia and of hypothermia treatment on the endocrine system, thus providing suggestions for improving the management of asphyxiated children.

Results

Involvement of the endocrine system (especially glucose and electrolyte disturbances, adrenal hemorrhage, non-thyroidal illness syndrome) can occur in a variable percentage of subjects with perinatal asphyxia, potentially affecting mortality as well as neurological outcome. Hypothermia may also affect endocrine homeostasis, leading to a decreased incidence of hypocalcemia and an increased risk of dilutional hyponatremia and hypercalcemia.

Conclusions

Metabolic abnormalities in the context of perinatal asphyxia are important modifiable factors that may be associated with a worse outcome. Therefore, clinicians should be aware of the possible occurrence of endocrine complication, in order to establish appropriate screening protocols and allow timely treatment.

Clinical insights of pregnancy management, adrenal insufficiency as a possible cause of elevated TSH: a pilot study of case series

BACKGROUND

The upper limit for thyroid-stimulating hormone has been strictly defined for pregnancy management, at which point levothyroxine replacement therapy will been initiated. However, it is essential to exclude adrenal insufficiency, including subclinical adrenal insufficiency, when initiating levothyroxine replacement therapy. However, in pregnancy management, it has rarely reported the incidence, clinical course, and characteristics of adrenal insufficiency as a possible cause of elevated thyroid-stimulating hormone.

METHODS

This case series study included pregnant patients undergoing thyroid-stimulating hormone management in a single-center diabetes endocrinology department between 2017 and 2020. The primary study outcome was the incidence of newly diagnosed adrenal insufficiency. We reported the clinical course and assessed the adrenal insufficiency characteristics at baseline and delivery and compared them with those of hypothyroidism.

RESULT

Fifteen pregnant women were included for thyroid-stimulating hormone management; and nine were below the basal serum cortisol level, and four were newly diagnosed as having adrenal insufficiency (26.7%) with the endocrinological stimulation test. Among them, two cases exhibited nausea and hypoglycemic symptoms after the start of levothyroxine replacement therapy. In cases of adrenal insufficiency, the patients were successfully treated with appropriate steroid coverage.

CONCLUSIONS

In the management of elevated thyroid-stimulating hormone levels during pregnancy, the frequency of adrenal insufficiency suspecting hypothyroidism may be higher than expected; therefore, we must be careful about starting levothyroxine replacement therapy for hypothyroidism. These clinical insights can have a significant impact on the pregnancy outcomes.

Harmonization of distributed multi-center analysis based on dried blood spot reference materials supporting the screening of neonatal inherited metabolic disorders

BACKGROUND

The standardization of quantification data is critical for ensuring the reliability and measurement traceability in the screening of neonatal inherited metabolic disorders. However, the availability of national certified reference materials is limited in China.

METHODS

In this study, we developed a series of dried blood spot (DBS) reference materials containing 9 amino acids (AA) and 10 acylcarnitines (AC) for neonatal screening. Four levels of the reference materials were measured with tandem mass spectrometry (MS/MS) by seven laboratories using different commercial In Vitro Diagnostic Device (IVD) kits. Then, 100 clinical samples were measured using both derivatization and non-derivatization methods by the same laboratory.

RESULTS

We found high homogeneity and stability at all levels of the reference materials, with the coefficient of variation (CV) of the analytes less than 15%. These reference materials can be used to assess the testing capabilities of different laboratories. Our test also revealed that the correction factors (CF) calculated by the reference materials, along with clinical samples, could increase the consistency for different kits.

CONCLUSION

The DBS reference materials proposed in this study provide reliability for the harmonization in multi-center analysis for the screening of neonatal inherited metabolic disorders. And applying our correction method for the screening could improve the data consistency of the DBS samples prepared by different methods.

Congenital hypothyroidism in Northern Ireland: 40 years' experience of national screening programme

OBJECTIVE

The incidence of congenital hypothyroidism (CHT) has progressively increased in several regions around the world but has yet to be evaluated in Northern Ireland (NI). CHT screening programme was introduced in NI in 1980 and has had a relatively unchanged protocol since its inception. The purpose of the study was to evaluate the incidence of CHT in NI from 1981 to 2020 and to explore possible contributing factors to any changes seen over the 40-year period.

DESIGN

This was a retrospective database review of children diagnosed with CHT in NI between 1981 and 2020. Data was collected from the patients' medical (paper and electronic) records, including epidemiological, clinical, laboratory, and radiological features as well as outcomes at 3 years.

RESULTS

Of 800,404 new-borns who were screened for CHT in NI between January 1981 and March 2020, 471 were diagnosed with CHT. There was a steady and significant increase in incidence of CHT over time with an incidence of 26 cases per 100,000 livebirths in 1981 versus 71 cases per 100,000 in 2019 (p < .001). Of these 471, 77 new-borns (16%) were born preterm. The incidence of CHT was observed twice as much in female compared to male new-borns. Diagnostic imaging including radioisotope uptake and thyroid ultrasound scans were performed in 143 cases (30%). Of these, 101 (70%) cases had thyroid dysgenesis and 42 (30%) cases had thyroid dyshormonogenesis. There were 293 (62%) of 471 patients had confirmed permanent CHT, and 90 patients (19%) had transient CHT. Over that period at least 95% of the population were recorded as having United Kingdom/Ireland as country of birth.

CONCLUSION

Our findings demonstrate a nearly tripling of the CHT incidence observed over the last 40 years. This is against a background of a relatively stable population demographics. Future research should focus on the underlying cause(s) of this condition which may include changing environmental exposures in utero.

The Association Between Hypoxic-Ischemic Encephalopathy and Thyroid Hormones

We aimed to compare serum thyroid-stimulating hormone (TSH) and free thyroxine (fT4) levels in neonates with different hypoxic-ischemic encephalopathy (HIE) stages undergoing therapeutic hypothermia (TH), and to evaluate the TSH and fT4 levels in neonates with HIE/TH in comparison with a control group. This was a retrospective study conducted between January 2020 and December 2022. The neonates with HIE/TH constituted the study group and the neonates with transient tachypnea of the newborn (TTN) constituted the control group. The study group consisted of neonates with stage 2 and stage 3 HIE. Serum TSH and fT4 levels measured at postnatal fifth day were compared between the groups. Of the 202 (47.1%) neonates included in the study group, 144 (71.3%) had stage 2 HIE and 58 (28.7%) had stage 3 HIE. In the control group, there were 227 (52.9%) newborns. Serum TSH and fT4 levels were found to be lower in the newborns with stage 3 HIE compared with those with stage 2 HIE (p = 0.015, 0.002, respectively). Although the serum TSH level was higher in the newborns with HIE compared with the newborns with TTN, serum fT4 levels did not change between the groups (p = < 0.001, 0.14, respectively). When we made the analysis according to the reference intervals, HIE/TH was associated with higher rates of TSH elevation compared with TTN, and the difference was more pronounced in stage 2 HIE/TH (p < 0.001). Although stage 3 HIE/TH was significantly associated with higher rates of low fT4 compared with TTN (p = 0.006), this relationship was not significant between stage 2 HIE/TH and TTN. It would be reasonable to interpret thyroid function tests performed on the fifth day with caution in newborns with HIE/TH, because higher TSH and lower fT4 levels on the fifth day in this patient group may result in unnecessary repetition of tests.

Homozygous Mutations in Thyroid Peroxidase (TPO) in Hypothyroidism with Intellectual Disability, Developmental Delay, and Hearing and Ocular Anomalies in Two Families: Severe Manifestation of Untreated TPO-deficiency Poses a Diagnostic Dilemma

Intellectual disability (ID) involves compromised intellectual, learning and cognitive skills, and behavioral capabilities with reduced psychomotor skills. One of the preventable causes of ID is congenital hypothyroidism (CH), which may be due to biallelic mutations in thyroid peroxidase (TPO). In low- and middle-income countries with no newborn screening programs, CH poses a great risk of ID and long-term morbidity. We report two large Pakistani families with a total of 16 patients afflicted with CH. Detailed clinical and behavioral assessments, SNP-based homozygosity mapping, linkage analysis, and exome sequencing were performed. Initially, affected individuals were referred as suffering ID (in 11 of 16 patients) and developmental delay (in 14). Secondary/associated features were verbal apraxia (in 13), goiter (in 12), short stature (in 11), limb hypotonia (in 14), no pubertal onset (five of 10 of age ≥14 years), high myopia (in eight), muscle cramps (in six), and in some, variable microcephaly and enuresis/encopresis, fits, chronic fatigue, and other behavioral symptoms, which are not characteristics of CH. Molecular genetic analyses led to the discovery of homozygous variants in TPO: novel missense variant c.719A>G (p.Asp240Gly) in family 1 and rare c.2315A>G (p.Tyr772Cys) in family 2. In low-resource countries where neonatal screening programs do not include a CH test, the burden of neurodevelopmental disorders is likely to be increased due to untreated CH. Secondly, in the background of the high prevalence of recessive disorders due to high parental consanguinity, the severe manifestation of TPO-deficiency mimics a wide range of neurological and other presentations posing a diagnostic dilemma.

Dynamic Screening of Thyroid Function for the Timely Diagnosis of Congenital Hypothyroidism in Very Preterm Infants: A Prospective Multicenter Cohort Study

Background: Preterm infants presented a high prevalence of congenital hypothyroidism (CH), while the optimal screening pattern is still under debate. This study aimed at evaluating the characteristics of thyroid function by conducting weekly screening during the first month of life in very preterm infants (VPIs) to achieve timely diagnosis and treatment of CH. Methods: A prospective cohort study was carried out on VPIs born with gestational age (GA) <32 weeks (w) and admitted to the participating institutes from January 1, 2019 to December 31, 2022. Serial serum thyroid hormone levels were measured weekly within the first month after birth, and at 36 w of corrected age, or before discharge. Datasets for serial thyroid hormone levels and general information were obtained. Results: A total of 5992 VPIs were enrolled in this study, of which 456 (7.6%) [95% confidence interval (CI), 6.9-8.3%] were diagnosed with CH. The incidence of CH increased with lower GA, moving from 4.8% [CI, 3.4-6.1%] at GA 31 w to 16.9% [CI, 8.3-25.4%] at GA <26 w. Among the CH subjects, 57.7% [CI, 53.1-62.2%] were identified after the first screening and classified as delayed thyrotropin elevation (dTSH). With the decrease of GA, the proportion of dTSH also increased, moving from 38.1% [CI, 27.5-48.7%] at GA 31 w to 82.6% [CI, 65.8-99.4%] at GA <26 w. Through conducting weekly screening of thyroid function, it was remarkable that only 42.3% [CI, 37.8-46.9%] of CH subjects were diagnosed during the first screening. The cumulative rate of CH identified by rescreening performed at the second, third, and fourth week was 76.1% [CI, 72.2-80.0%], 90.6% [CI, 87.9-93.3%], and 98.9% [CI, 97.9-99.9%], respectively. Conclusion: The incidence of CH and dTSH both increase with lower GA in VPIs. Dynamic screening of thyroid function by weeks within the first month of life is crucial for the timely diagnosis and treatment of CH in VPIs, and it might effectively reduce the implications of missed diagnosis and delayed treatment. Clinical Trials Registration: ChiCTR1900025234 and ChiCTR2000037918 (Registration number).

A novel variant of THRβ and its 4-year clinical course in a Korean boy with resistance to thyroid hormone

Thyroid hormone resistance (RTH) is characterized by a decreased sensitivity of target tissues to thyroid hormones due to a defect in the THRα- and THRβ-encoded thyroid hormone receptors (THRs). The clinical manifestations range from no symptoms to simple goiter and hypo- or hyperthyroidism, depending on the receptor subtype distribution in the tissues. Here, we report the case of a thyroid hormone-resistant 12-month-old boy carrying a novel THRβ variant who was initially diagnosed with congenital hypothyroidism. An extensive evaluation revealed increased free T4 level and inappropriately increased thyroid-stimulating hormone (TSH) level; a normal lipid profile, sex hormone-binding globulin, and free alpha subunit of TSH; exaggerated TSH response to THR; and no radiological evidence of pituitary adenoma. A targeted next-generation sequencing panel identified a heterozygote c.993T>G (p.Asn331Lys) mutation in the THRβ gene. During the first year of life, a higher dose of levothyroxine was administered to the patient due to uncompensated RTH. Levothyroxine treatment was continued after 3 years to maintain TSH level <5 mIU/mL, but the observed weight gain was poor, height increase was insufficient, and bone development was delayed. However, neither hyperactivity nor developmental delay was observed. Patients with RTH exhibit various clinical features. Due to its heterogeneous nature, genetic test for accurate diagnosis is important to provide proper management.

Thyroid Stimulating Hormone and Thyroid Hormones (Triiodothyronine and Thyroxine): An American Thyroid Association-Commissioned Review of Current Clinical and Laboratory Status

Background: Despite being the most performed laboratory endocrine investigation, the optimum use of thyroid tests (thyrotropin [TSH] and thyroid hormone [TH] measurement) is open to question and the interpretation of the results from these tests can be ambiguous. The American Thyroid Association (ATA) with its expertise support the endeavor of the U.S. Centers for Disease Control (CDC) and the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) to improve and maintain standardization and harmonization of thyroid testing. ATA mandated an international interdisciplinary working group panel to survey the status of thyroid testing by reviewing the recent literature to revise or update the criteria as needed in mutual agreement and to inform clinical care. Summary: This review represents the conclusions on the clinical use of current routine TSH and TH (thyroxine [T4] and triiodothyronine [T3]) assays, taking into account geographic differences in disease prevalence and clinical and laboratory practice among writing members. The interaction between physiological, pathophysiological, and pharmacological factors and thyroid assays can affect their measurements and confound result interpretation. These factors need to be considered in the clinical context of the patient for appropriate test ordering and result interpretation. Despite significant advances in laboratory methods over the past 50 years, routine thyroid assays remain susceptible to idiosyncratic analytical interference that may produce spurious results. Improved standardization needs to be demonstrated through ongoing international efforts before results from different assays can be considered equivalent. Emerging technology (e.g., mass spectrometry) shows promise for improved analytical performance, but more evidence of its clinical utility and improved throughput is required before it can be considered for routine use. Close clinical-laboratory collaboration is encouraged to overcome and avoid the pitfalls in thyroid testing as well as resolve clinically discrepant results. The evidence base supporting the conclusions of this review is summarized in four detailed online technical supplements. Conclusions: Over the past five decades, testing for TSH, T4, and T3 has evolved from manual radioisotopic immunoassays to nonisotopic multiplexed immunometric assays using highly automated equipment. Despite these technical advances, physicians and laboratorians performing these analyses must understand limitations of these methods to properly order tests and interpret results.

Etiological Profile, Targeted Levothyroxine Dosing and Impact of Partial Newborn Screening in Congenital Hypothyroidism-A Single Centre Experience

Background

Congenital hypothyroidism (CH) is the most common cause of preventable intellectual disability. Newborn screening (NBS) for CH has been in vogue in many parts of the world since 1970, but despite its well-known benefits, many developing countries including India have not been able to establish universal NBS for CH till date.

Objective

The aim of this study was to review the clinical aspects of congenital hypothyroidism in a tertiary care university referral teaching hospital, focusing on aetiology of CH, predictors of permanence, optimal targeted dose strategies based on aetiology and the effect of newborn screening on the time to diagnosis.

Material and Methods

The electronic medical records of 233 children with CH referred to our centre between January 2009 and December 2019 were analysed. A partial NBS was established in the state in 2012.

Results

Dyshormonogenesis (57.5%) was the most common aetiology of CH. The incidence of transient CH in children with a gland in situ (GIS) was 35%. Levothyroxine (LT-4) dose of >2.75 μg/kg/day (sensitivity 76.5, specificity 72), >2.15 μg/kg/day (sensitivity 82.4, specificity 61.9) and >1.85 μg/kg/day (sensitivity 76.5, specificity 61.9) at years 1, 2 and 3, respectively, were predictors of permanent CH. An initial LT-4 dose ≥8 μg/kg was sufficient and very seldom led to undertreatment in children with dyshormonogenesis. On the contrary, even doses ≥13 mcg/kg/day led to frequent undertreatment in children with thyroid dysgenesis. After the introduction of newborn screening, the median age at diagnosis came down from 45 days (IQR 14-180 days) to ten days (IQR 3-12 days).

Conclusion

Targeted dosing based on aetiology of CH may be more appropriate to optimise outcomes. The time to diagnosis of CH reduced significantly after the adoption of even a partial NBS program highlighting the urgent need for implementation of the same in resource poor settings.

Clinical indicators that influence a clinician's decision to start L-thyroxine treatment in prematurity with transient hypothyroxinemia

BACKGROUND

Transient hypothyroxinemia of prematurity (THOP) is defined as a low level of circulating thyroxine (T4), despite low or normal thyroid-stimulating hormone (TSH) levels.

AIMS

We aimed to evaluate the incidence of THOP, the clinical and laboratory findings of preterm infants with this condition and the levothyroxine (L-T4) treatment.

METHODS

Preterm infants (n = 181) delivered at 24-34 weeks of gestation were evaluated by their thyroid function tests that were performed between the 10th and 20th days of postnatal life and interpreted according to the gestational age (GA) references. Clinical and laboratory characteristics of the patients with THOP and normal thyroid function tests were compared. Patients with THOP and treated with L-T4 were compared with the ones who were not regarding laboratory, and clinical characteristics.

RESULTS

Incidence of hypothyroxinemia of prematurity was 45.8% (n = 83). Euthyroidism, primary hypothyroidism, and subclinical hypothyroidism were diagnosed in 47.5% (n = 86), 5% (n = 9) and 1.7% (n = 3) of the patients, respectively. Mean birth weight (BW) and GA were significantly lower in the hypothyroxinemia group than in the euthyroid group (p < 0.001). L-T4 was started in 43% (n = 36) of the patients with THOP. Treatment initiation rate was 44.4% (n = 16) in 24-27 wk, 41.6% (n = 15) in 28-30 wk, and 13.8% (n = 5) in 31-34 wk. As the GA increased, the incidence of THOP and the rate of treatment initiation decreased (p < 0.001). The lowest free thyroxine (FT4) cut-off value was 0.72 ng/dl in the treated group. In addition, incidences of vancomycin + amikacin, caffeine, dopamine treatments, RDS, IVH, BPD, central catheter, FFP transfusion, and ventilator support were higher in the treated group (P < 0.05).

CONCLUSION

This study revealed that prevalence of THOP increased as the GA and BW decreased. As the GA decreased, THOP patients requiring L-T4 treatment increased. Additionally, association with comorbid diseases increased the requirement of treatment.

Hypothyroidism in First-Degree Relatives of Neonates with Congenital Hypothyroidism: Is there an Association?

Background

Recent studies have shown an increased incidence of congenital hypothyroidism (CH), especially in the middle-east region. The exact etiology is unknown; however, it has been related to several factors, the most noticeable being the high prevalence of transient CH (TCH), parental consanguinity, and the history of hypothyroidism in relatives. We sought to determine the impact of hypothyroidism in the relatives of patients with the observed trend.

Methods

We included all patients with primary CH detected through the Newborn Screening (NBS) Program from 2007 to 2016. We analyzed the impact of consanguinity relationship, parental and siblings' thyroid function, second-degree relatives' thyroid function, parental educational level, age, and maternal gestational diabetes on the development of permanent CH (PCH) and TCH.

Results

A total of 1447 consecutive eligible patients were recruited during the study period. Of this number, 1171 (81%) were diagnosed with CH: 623 (53.2%) had PCH and 548 (46.8%) had TCH. Six hundred thirty-three (54.1%) participants were men, and 814 (69.5%) had a history of relatives' hypothyroidism. Our data analysis revealed a significant difference regarding the male gender, having a history of relatives' hypothyroidism, and parental hypothyroidism compared to TCH ones (P < 0.05). Patients with a history of relatives' hypothyroidism had significantly higher PCH than TCH (P < 0.0001). However, consanguineous marriage was not comparable in patients regardless of their history of relatives' hypothyroidism (P-value >0.884).

Conclusions

Our findings indicated the role of the history of hypothyroidism in neonates' relatives in the evolution of the PCH. Meanwhile, consanguineous marriage did not impress the development of PCH and TCH.

Congenital hypothyroidism in Bogotá, Colombia: a current description (2015-2021)

OBJECTIVES

Congenital hypothyroidism (CH) is a decrease in thyroid hormone function in newborns, being one of the leading causes of neurological deficits and long-term metabolic complications. This study aims to determine the prevalence and characteristics of CH cases in Bogotá, Colombia, between 2015 and 2021, as notified through the mandatory report to the Public Health Surveillance System (PHSS).

METHODS

A retrospective cross-sectional study was conducted. All live births (LB) with a weight ≥500 g, diagnosed with CH with or without goiter (ICD-10 codes E030 and E031, respectively) in Bogotá during 2015-2021 were analyzed.

RESULTS

For a total of 201 cases, the prevalence rate was 3.29 cases per 10,000 LB. 92.54 % were classified as isolated cases of CH, 4.48 % syndromic, and 2.98 % polymalformated. A total of 16.92 % was small for gestational age. The mean gestational age was 37.38 weeks (SD 2.76), 26.87 % were preterm births. Among the mothers, 8.96 % suffered from pregnancy-related or chronic diseases, the most common being hypertensive disorders of pregnancy and pre-existant hypothyroidism (without clarity concerning etiology). A total of 66.67 % of cases did not receive treatment after diagnosis. Treatment was established by an average age of 27 days after birth (SD 36.02) and 17 days after case notification to the PHSS (SD 36.13).

CONCLUSIONS

Observed prevalence is similar to the rate reported by health authorities in Colombia but inferior to reports from high-income countries, highlighting the importance of improvements in the Colombian LB's screening program. Time to diagnosis and treatment was observed to be prolonged, suggesting that new pathways are required for timely CH treatment.

The Severity of Congenital Hypothyroidism With Gland-In-Situ Predicts Molecular Yield by Targeted Next-Generation Sequencing

INTRODUCTION

Congenital hypothyroidism with gland-in-situ (CH-GIS) is usually attributed to mutations in the genes involved in thyroid hormone production. The diagnostic yield of targeted next-generation sequencing (NGS) varied widely between studies. We hypothesized that the molecular yield of targeted NGS would depend on the severity of CH.

METHODS

Targeted NGS was performed in 103 CH-GIS patients from the French national screening program referred to the Reference Center for Rare Thyroid Diseases of Angers University Hospital. The custom targeted NGS panel contained 48 genes. Cases were classified as solved or probably solved depending on the known inheritance of the gene, the classification of the variants according to the American College of Medical Genetics and Genomics, the familial segregation, and published functional studies. Thyroid-stimulating hormone at CH screening and at diagnosis (TSHsc and TSHdg) and free T4 at diagnosis (FT4dg) were recorded.

RESULTS

NGS identified 95 variants in 10 genes in 73 of the 103 patients, resulting in 25 solved cases and 18 probably solved cases. They were mainly due to mutations in the TG (n = 20) and TPO (n = 15) genes. The molecular yield was, respectively, 73% and 25% if TSHsc was ≥ and < 80 mUI/L, 60% and 30% if TSHdg was ≥ and < 100 mUI/L, and 69% and 29% if FT4dg was ≤ and > 5 pmol/L.

CONCLUSION

NGS in patients with CH-GIS in France found a molecular explanation in 42% of the cases, increasing to 70% when TSHsc was ≥ 80 mUI/L or FT4dg was ≤ 5 pmol/L.

Thyroid Nodules in Children and Adolescents: A Single Institution's Experience

OBJECTIVE

The risk of malignancy in pediatric thyroid nodules is higher compared to the risk in adults. Our aim was to investigate the clinical, radiological, and histopathological characteristics of pediatric thyroid nodules.

MATERIALS AND METHODS

The data of 132 children and adolescents who had thyroid nodules were collected retrospectively from medical records.

RESULTS

The mean age of the patients was 12.07 ± 4.08 years and 67% were female. Fine-needle aspiration biopsy was performed in 86 patients (65%) and the results were as follows: benign in 53.4% (n = 46), atypia or follicular lesion of undetermined significance in 3.5% (n = 3), suspicious for follicular neoplasia in 2.3% (n = 2), and malignancy in 32.5% (n = 28). The overall malignancy rate was 22.7% (n = 30). Malignancy was detected after surgery in 2 thyroid nodules belonging to the atypia or follicular lesion of undetermined significance category. Malignancy was detected in 7 patients who had autoimmune thyroiditis and in 1 patient who had congenital dyshormonogenesis. The malignancy rate of the nodules in the patients, who had autoimmune thyroiditis, was found to be 13.4%. Mixed echogenicity, microcalcifications, nodules larger than 10 mm, abnormal lymph nodes, and irregular borders were more common in the malignant group. The nodule size, abnormal lymph nodes, and irregular borders were found to be significant in terms of predicting malignancy.

CONCLUSION

We found malignancy in 22.7% of the thyroid nodules, and the malignancy rate of nodules in the patients, who had autoimmune thyroiditis, was 13.4%. The nodule size, abnormal lymph nodes, and irregular nodule borders emerged as the most significant risk factors for malignancy.

Inflammation and Immune Reactions in the Fetus as a Response to COVID-19 in the Mother

Background: Contracting COVID-19 during pregnancy can harm both the mother and the unborn child. Pregnant women are highly likely to develop respiratory viral infection complications with critical conditions caused by physiological changes in the immune and cardiopulmonary systems. Asymptomatic COVID-19 in pregnant women may be accompanied by fetal inflammatory response syndrome, which has adverse consequences for the newborn's life and health. Purpose: To conduct an inflammatory response assessment of the fetus due to the effects of COVID-19 on the mother during pregnancy by determining pro-inflammatory cytokines, cell markers, T regulatory cells, T cell response, evaluation of cardiac function, and thymus size. Materials and methods: A prospective study included pregnant women (n = 92). The main group consisted of 62 pregnant women with COVID-19 infection: subgroup 1-SARS-CoV-2 PCR-positive pregnant women 4-6 weeks before delivery (n = 30); subgroup 2-SARS-CoV-2 PCR-positive earlier during pregnancy (n = 32). The control group consisted of 30 healthy pregnant women. In all pregnant women, the levels of circulating cytokines and chemokines (IL-1α, IL-6, IL-8, IL-10, GM-CSF, TNF-α, IFN-γ, MIP-1β, and CXCL-10) were determined in the peripheral blood and after delivery in the umbilical cord blood, and an analysis was performed of the cell markers on dendritic cells, quantitative and functional characteristics of T regulatory cells, and specific T cell responses. The levels of thyroxine and thyroid-stimulating hormone were determined in the newborns of the studied groups, and ultrasound examinations of the thymus and echocardiography of the heart were also performed. Results: The cord blood dendritic cells of newborns born to mothers who suffered from COVID-19 4-6 weeks before delivery (subgroup 1) showed a significant increase in CD80 and CD86 expression compared to the control group (p = 0.023). In the umbilical cord blood samples of children whose mothers tested positive for COVID-19 4-6 weeks before delivery (subgroup 1), the CD4+CCR7+ T cells increased with a concomitant decrease in the proportion of naive CD4+ T cells compared with the control group (p = 0.016). Significantly higher levels of pro-inflammatory cytokines and chemokines were detected in the newborns of subgroup 1 compared to the control group. In the newborns of subgroup 1, the functional activity of T regulatory cells was suppressed, compared with the newborns of the control group (p < 0.001). In all pregnant women with a severe coronavirus infection, a weak T cell response was detected in them as well as in their newborns. In newborns whose mothers suffered a coronavirus infection, a decrease in thymus size, transient hypothyroxinemia, and changes in functional parameters according to echocardiography were revealed compared with the newborns of the control group. Conclusions: Fetal inflammatory response syndrome can occur in infants whose mothers suffered from a COVID-19 infection during pregnancy and is characterized by the activation of the fetal immune system and increased production of pro-inflammatory cytokines. The disease severity in a pregnant woman does not correlate with SIRS severity in the neonatal period. It can vary from minimal laboratory parameter changes to the development of complications in the organs and systems of the fetus and newborn.

Utility of basal and peak TSH values in TRH stimulation testing for predicting the long-term therapeutic prognosis of primary congenital hypothyroidism

In Japan, most neonates undergo screening for congenital hypothyroidism (CH). A TRH stimulation test (TRH-T) may be performed after initial treatment as a useful method for reevaluating the patient's thyroid status. However, no studies have compared basal and peak TSH values in TRH-T in patients with long-term follow-up. This was a retrospective and observational study. The inclusion criteria were as follows: (1) CH diagnosis based on positive newborn screening, (2) follow-up > 15 yr, and (3) TRH-T after LT4 discontinuation. The participants were divided into a no-treatment group (No-T group) and a treatment group (T group). The No-T and T groups included 14 and nine patients, respectively. The age at TRH-T was 5.38 yr for the No-T group and 4.25 yr for the T group, with no significant difference. The basal and peak TSH levels were significantly lower in the No-T group. The areas under the Receiver operating characteristic curve for basal and peak TSH values were 0.984 and 0.905, respectively. When the basal TSH level was under 4.594 IU/mL, the No-T group had a sensitivity of 1.00 and a specificity of 0.93. Basal TSH levels alone may be sufficient for predicting the long-term therapeutic prognosis of patients with CH.

Outcomes of lowered newborn screening thresholds for congenital hypothyroidism

BACKGROUND

Newborn screening (NBS) has largely eliminated the physical and neurodevelopmental effects of untreated congenital hypothyroidism (CH). Many countries, including Australia, have progressively lowered NBS bloodspot thyroid-stimulating hormone (b-TSH) thresholds. The impact of these changes is still unclear.

OBJECTIVES

To evaluate the performance of CH NBS following the reduction of b-TSH thresholds in New South Wales (NSW) and the Australian Capital Territory (ACT), Australia, from 15 to 8 mIU/L, and to determine the clinical outcomes of cases detected by these thresholds.

METHODS

NBS data of 346 849 infants born in NSW/ACT, Australia from 1 November, 2016-1 March, 2020 inclusive were analysed. A clinical audit was conducted on infants with a preliminary diagnosis of CH born between 1 January, 2016-1 December, 2020 inclusive.

RESULTS

The lowered b-TSH threshold (≥8 mIU/L, ~99.5th centile) detected 1668 infants (0.48%), representing an eight-fold increase in recall rate, of whom 212 of 1668 (12.7%) commenced thyroxine treatment. Of these 212 infants, 62 (29.2%) (including eight cases with a preliminary diagnosis of thyroid dysgenesis) had an initial b-TSH 8-14.9 mIU/L. The positive predictive value for a preliminary diagnosis of CH decreased from 74.3% to 12.8% with the lowered threshold. Proportionally, more pre-term infants received a preliminary CH diagnosis on screening with the lower threshold (16.1% of 62) than with the higher threshold (8.0% of 150).

CONCLUSION

Clinically relevant CH was detected using the lowered threshold, albeit at the cost of an eight-fold increase in recall rate. Further clinical and economic studies are required to determine whether benefits of lowered screening thresholds outweigh potential harms from false-positive results on infants, their families and NBS programs.

Epidemiological profile of congenital hypothyroidism at a southern Brazilian state

Objective

To determine the incidence of congenital hypothyroidism (CH) over a 10-year period at the Reference Service in Neonatal Screening of the state of Rio Grande do Sul (RSNS-RS).

Subjects and methods

Historical cohort study including all newborns screened for CH by the RSNS-RS from January 2008 until December 2017. Data of all newborns with neonatal TSH (neoTSH; heel prick test) values ≥ 9 mIU/L were collected. According to neoTSH values, the newborns were allocated into two groups: Group 1 (G1), comprising newborns with neoTSH ≥ 9 mIU/L and serum TSH (sTSH) < 10 mIU/L, and Group 2 (G2), comprising those with neoTSH ≥ 9 mIU/L and sTSH ≥ 10 mIU/L.

Results

Of 1,043,565 newborns screened, 829 (0.08%) had neoTSH values ≥ 9 mIU/L. Of these, 284 (39.3%) had sTSH values < 10 mIU/L and were allocated to the G1 group, while 439 (60.7%) had sTSH ≥ 10 mIU/L and were allocated to the G2 group, and 106 (12.7%) were considered missing data. The overall incidence of CH was 42.1 per 100,000 newborns screened (95% confidence interval [CI] 38.5-45.7/100,000) or 1:2377 screened newborns. The sensibility and specificity of neoTSH ≥ 9 mIU/L were 97% and 11%; of neoTSH 12.6 mUI/L, 73% and 85% respectively.

Conclusion

In this population, the incidence of permanent and transitory CH was 1:2377 screened newborns. The neoTSH cutoff value adopted during the study period showed excellent sensibility, which matters for a screening test.

Combined genetic screening and traditional newborn screening to improve the screening efficiency of congenital hypothyroidism

Background

Congenital hypothyroidism (CH) is an neonatal endocrine disorder. Traditional newborn screening is the mainstream method of CH screening, so as to ensure the early detection and treatment of CH. This method is limited as it has high rates of false positives and negatives. Genetic screening can be used to address the shortcomings of traditional newborn Screening (NBS); however, the comprehensive clinical value of genetic screening is yet to be systematically studied.

Methods

A total of 3,158 newborns who accepted the newborn screening and genetic screening were recruited for this study. Biochemical screening and genetic screening were performed at the same time. The level of TSH with the DBS was detected by time-resolved immunofluorescence assay. High-throughput sequencing technology based on targeted gene capture was used for genetic screening. The suspected neonatal was recalled and tested serum TSH, and FT4. Finally, the effectiveness of traditional NBS and combined screening was compared.

Results

In this study, 16 cases were diagnosed by traditional NBS. 10 cases of DUOX2 mutation were found in newborn CH-related genetic screening, including 5 homozygous and 5 compound heterozygous variations. We found that the c.1588A > T mutations in DUOX2 constituting the predominant site in the present cohort.Compared with NBS and genetic screening, the sensitivity of combined screening increased by 11.1% and 55.6%, respectively. Compared with NBS and genetic screening, the negative predictive value of combined screening increased by 0.1% and 0.4%, respectively.

Conclusions

Combined traditional NBS and genetic screening reduces the false negative rate of CH screening and improves the early and accurate identification of neonates with CH. Our research explains the mutation spectrum of CH in this region, and provisionally demonstrates the necessity, feasibility and significance of genetic screening in newborns and provides a solid basis for future clinical developments.

The p.Cys1281Tyr variant in the hinge module/flap region of thyroglobulin causes intracellular transport disorder and congenital hypothyroidism

Congenital hypothyroidism (CH) due to thyroglobulin (TG) variants causes very low serum TG levels with normal or enlarged thyroid glands, depending on the severity of the defect, and with autosomal recessive inheritance. The purpose of this study was to functionally characterize p.Cys1281Tyr variant in the TG gene in order to increase our knowledge of the molecular mechanisms associated with CH. In order to find evidence that support the hypothesis that the p.Cys1281Tyr variant would affect the TG folding were performed amino acid prediction, 3D modeling and transient expression analysis in HEK293T cells. 18 of the 21″in silico" algorithms predict a deleterious effect of the p.Cys1281Tyr variant. The full-length 3D model p.Cys1281Tyr TG showed disulfide bond cleavage between the cysteines at positions 1249 and 1281 and rearrangement of the TG structure, while transient expression analysis indicated that p.Cys1281Tyr causes retention of the protein inside the cell. Consequently, these results show that this pathogenic variant makes it impossible for TG to fulfill its function in the biosynthesis process of thyroid hormones, causing CH. In conclusion, our results confirm the pathophysiological importance of misfolding of TG as a consequence of p.Cys1281Tyr variant located in the hinge module/flap region of TG.

Fetal Thyrotoxicosis due to Maternal TSH Receptor Stimulating Antibodies Causes Infant Central Hypothyroidism

INTRODUCTION

Women with a current diagnosis or past history of Graves' disease (GD) are at risk of developing fetal thyrotoxicosis (FT) during pregnancy when they are inadequately treated, or because of placental passage of TSH receptor antibodies (TRAb). It is known that FT induced by high maternal thyroid hormone concentrations may result in infant (central) hypothyroidism.

CASE PRESENTATION

In a euthyroid woman with a history of GD treated with radioactive iodide (I131), persistently high levels of maternal TRAb resulted in recurrent FT during two separate pregnancies, followed by neonatal hyperthyroidism and infant central hypothyroidism.

DISCUSSION

This case demonstrates the novel insight that FT due to high fetal thyroid hormone concentrations stimulated by high maternal TRAb levels might also result in (central) hypothyroidism, requiring long-term evaluation of the hypothalamus-pituitary-thyroid axis in these children.