Congenital hypothyroidism

Congenital hypothyroidism and risk of subsequent autism spectrum disorder and attention-deficit/hyperactivity disorder in Taiwan

AIM

Evidence suggests an association between maternal hypothyroidism and risk of attention-deficit/hyperactivity disorder (ADHD) or autism spectrum disorder (ASD) in offspring. We examined the risk of ASD and ADHD in individuals with congenital hypothyroidism (CHT).

METHODS

A nationwide population-based cohort study enrolled a total of 1260 children younger than 12 years with a confirmed diagnosis of CHT and no prior diagnosis of any neurodevelopmental disorders, selected from the National Health Insurance Research Database of Taiwan between 1998 to 2013. In addition, 12,600 controls matched for sex, age, and residence were selected. Cox proportional hazards analysis was used to investigate the association among CHT, ASD, and ADHD.

RESULTS

Children with CHT were associated with a higher incidence of ASD (7.1‰ vs 1.3‰, P < 0.001) and ADHD (39.7‰ vs 18.7‰, P < 0.001) than the control group. Cox regression analyses demonstrated that children with CHT were associated with elevated risks of ASD (hazard ratio [HR], 4.72 [95% confidence interval (CI), 2.08-10.70]) and ADHD (HR, 2.03 [95% CI, 1.49-2.77]), after adjusting for demographic data and family history of major psychiatric disorders, compared with the control group.

CONCLUSION

Children with CHT were associated with approximately a two-fold increased risk of ADHD and a four-fold increased risk of ASD than the control group. Our study highlights the need for future research to elucidate the potential pathophysiology among CHD, ASD, and ADHD.

Exploring mammalian heme peroxidases: A comprehensive review on the structure and function of myeloperoxidase, lactoperoxidase, eosinophil peroxidase, thyroid peroxidase and peroxidasin

The peroxidase family of enzymes is a ubiquitous cluster of enzymes primarily responsible for the oxidation of organic and inorganic substrates. The mammalian heme peroxidase subfamily is characterized by a covalently linked heme prosthetic group which plays a key role in the oxidation of halides and psuedohalides into their respective hypohalous acid and hypothiocyanous acid under the influence of H2O2 as substrate. The members of the heme peroxidase family include Lactoperoxidase (LPO), Eosinophil peroxidase (EPO), Myeloperoxidase (MPO), Thyroid peroxidase (TPO) and Peroxidasin (PXDN). The biological activity of LPO, MPO and EPO pertains to antibacterial, antifungal and antiviral while TPO is involved in the biosynthesis of the thyroid hormone and PXDN helps maintain the ECM. While these enzymes play several immunomodulatory roles, aberrations in their activity have been implicated in diseases such as myocardial infarction, asthma and Alzheimer's amongst others. The sequence and structural similarities amongst the members of the family are strikingly high while the substrate specificities and subcellular locations vary. Hence, it becomes important to provide a consortium of information regarding the members to study their biochemical, pathological and clinical function.

Brain Abnormalities in Young Single- and Double-Heterozygote Mice for Both Nkx2-1- and Pax8-Null Mutations

In humans and mice, Nkx2-1 and Pax8 are crucial morphogenic transcription factors defining the early development of the thyroid and specific extrathyroidal tissues. By using 3-month-old single or double heterozygotes for Nkx2-1- and Pax8-null mutations (DHTP) mice, we studied brain abnormalities under different human-like dysthyroidisms, focusing on putative alterations of specific neurotransmitter systems, expression of markers of pre- and post-synaptic function and, given the physio-pathological role mitochondria have in controlling the bioenergetic status of neurons, of mitochondrial dynamics and oxidative balance. Compared to Wt controls, DHTP mice, bearing both systemic and brain hypothyroidism, showed altered expression of synaptic markers, generic and cholinergic (corroborated by immunohistochemistry in caudate, putamen, hippocampus, and basal forebrain) and glutamatergic ones, and reduced expression of key proteins of synaptic plasticity potency and several isoforms of glutamate receptors. The brain of DHTP mice was characterized by lower levels of H2O2 and imbalanced mitochondrial dynamics. Nkx2-1 + / - mice showed dopaminergic neuron-specific alterations, morphologically, more evident in the substantia nigra of DHTP mice. Nkx2-1 + / - mice also showed enhanced mitochondrial biogenesis and oxidative capacity likely as a global response of the brain to Nkx2-1 haploinsufficiency and/or to their elevated T3 circulating levels. Reduced transcription of both tyrosine hydroxylase and dopamine transporter was observed in Pax8 + / - euthyroid mice, suggesting a dopaminergic dysfunction, albeit likely at an early stage, but consistent with the deregulated glucose homeostasis observed in such animals. Overall, new information was obtained on the impact of haploinsufficiency of Pax8 and NKx2-1 on several brain neuroanatomical, molecular, and neurochemical aspects, thus opening the way for future targeting brain dysfunctions in the management of both overt and subclinical thyroid dysfunctions.

Genetic and Functional Studies of Patients with Thyroid Dyshormonogenesis and Defects in the TSH Receptor (TSHR)

Genetic defects in the TSH receptor (TSHR) can cause poor thyroid differentiation (thyroid dysgenesis) and/or thyroid malfunction (thyroid dyshormonogenesis). The phenotype spectrum is wide: from severe congenital hypothyroidism to mild hyperthyrotropinemia. Over 250 TSHR variants have been published, many uncharacterized in vitro. We aimed to genetically characterize patients with thyroid dyshormonogenesis with TSHR defects and to study in vitro the effect of the genetic variants to establish the genotype-phenotype relationship. Pediatric patients with thyroid dyshormonogenesis (160 patients, Catalan CH neonatal screening program, confirmation TSH range: 18.4-100 mIU/L), were analyzed by a high-throughput gene panel. In vitro studies measuring the TSH-dependent cAMP-response-element activation were performed. Five patients with mild or severe thyroid dyshormonogenesis presented six TSHR variants, two unpublished. Each variant showed a different in vitro functional profile that was totally or partially deleterious. Depending on the genotype, some of the variants showed partial deficiency in both genotypes, whereas others presented a different effect. In conclusion, the percentage of patients with thyroid dyshormonogenesis and candidate variants in TSHR is 3.13%. Our in vitro studies contributed to the confirmation of the pathogenicity of the variants and highlighted the importance of studying the effect of the patient's genotype for a correct diagnostic confirmation.

Diagnostic options, physiopathology, risk factors and genetic causes of permanent congenital hypothyroidism: A narrative review

Background

In Permanent congenital hypothyroidism (PCH) is a lifelong condition characterized by a deficiency in thyroid hormone, leading to various neurodevelopmental complications. Early clinical signs are often nonspecific and easily overlooked, but newborn screening programs have improved early detection.

Methods

This narrative review aims to provide insights comparatively transient and permanent PCH and also the diagnosis, risk factors, underlying pathophysiology, and genetic causes associated with PCH. Relevant studies were identified through a comprehensive search using the term 'Permanent congenital hypothyroidism' (Mesh) across scientific databases of electronic databases such as PubMed, Scopus, and Web of Science.

Results

Prompt initiation of thyroid hormone replacement therapy, particularly within the initial two weeks postpartum, crucially enhances neurocognitive development outcomes. Multiple predictive approaches, encompassing screening TSH levels, maternal thyroid history, and levothyroxine dosage per kilogram assessment, aid in identifying PCH. Recent studies have demonstrated a mounting prevalence of PCH, contributing significantly to the overall rise in CH incidence. Genetic factors, primarily DUOX2 and DUOXA2 mutations, alongside environmental influences such as post-term birth, low birth weight, and macrosomia, may induce PCH. Nonetheless, reliable markers for early PCH prediction upon diagnosis remain elusive, leading to delayed recognition post-ceasing levothyroxine treatment around age 3.

Conclusions

Recent studies have observed an increased incidence of PCH, contributing substantially to the overall rise in cases of congenital hypothyroidism. Understanding the diagnostic options and genetic etiologies associated with PCH is crucial for the early identification and appropriate management.

Association between maternal hypothyroidism, baby birth weight, and adult cardiovascular disease risk: insights from ECG measurements

OBJECTIVES

Thyroid hormone (TH) deficiency during pregnancy may affect cardiovascular function in offspring rats. This study aimed to evaluate the effect of TH deficiency during gestation, on the electrocardiogram indices of young and middle-aged offspring of male rats.

METHODS

Eight female rats were equally divided into hypothyroid and control groups. The hypothyroid mothers received 0.025% 6-propyl-2-thiouracil (PTU) in drinking water throughout pregnancy, while control mothers consumed only tap water. Following birth, male rats from each group were observed for 4 months (young age) and 12 months (middle-aged). The group known as fetal hypothyroid (FH) consisted of rats born from hypothyroid mothers. The serum T4 and TSH concentrations from mothers and newborn male rats were assayed at the end of gestation. Lead II electrocardiogram (ECG) was recorded for 5 minutes using Power Lab, AD Instruments.

RESULTS

There was a significant rise in the P wave voltage in young FH rats, whereas, it was decreased in middle-aged control and FH rats. The voltage of QRS decreased and its duration increased in the young and middle-aged FH rats compared to the corresponding control groups. Duration and voltage of the T wave were significantly altered in the young and middle-aged FH groups. PR and QT intervals significantly increased in the young and middle-aged FH groups compared to their controls.

CONCLUSIONS

Maternal hypothyroidism affected the electrocardiogram indices of offspring rats, possibly signaling cardiovascular problems later in life.

Patients with Thyroid Dyshormonogenesis and DUOX2 Variants: Molecular and Clinical Description and Genotype-Phenotype Correlation

Thyroid dyshormonogenesis (THD) is a heterogeneous group of genetic diseases caused by the total or partial defect in the synthesis or secretion of thyroid hormones. Genetic variants in DUOX2 can cause partial to total iodination organification defects and clinical heterogeneity, from transient to permanent congenital hypothyroidism. The aim of this study was to undertake a molecular characterization and genotype-phenotype correlation in patients with THD and candidate variants in DUOX2. A total of 31 (19.38%) patients from the Catalan Neonatal Screening Program presented with variants in DUOX2 that could explain their phenotype. Fifteen (48.39%) patients were compound heterozygous, 10 (32.26%) heterozygous, and 4 (12.90%) homozygous. In addition, 8 (26.67%) of these patients presented variants in other genes. A total of 35 variants were described, 10 (28.57%) of these variants have not been previously reported in literature. The most frequent variant in our cohort was c.2895_2898del/p.(Phe966SerfsTer29), classified as pathogenic according to reported functional studies. The final diagnosis of this cohort was permanent THD in 21 patients and transient THD in 10, according to reevaluation and/or need for treatment with levothyroxine. A clear genotype-phenotype correlation could not be identified; therefore, functional studies are necessary to confirm the pathogenicity of the variants.

Genetic etiology in patients diagnosed with congenital hypothyroidism with new-generation sequencing: A single-center experience

AIM

Congenital hypothyroidism (CH) is the most common endocrine disorder of the newborn; it is seen in every 3000-4000 births. Genetic features can guide treatment for patients with in situ glands. The present study aimed to contribute to the literature on CH variants and to show the benefit that genetic analysis can provide to patients in follow-up.

METHOD

A total of 52 patients (47 families) diagnosed with CH were included in the study. Overall, 32 target genes involved in thyroid physiology were investigated by next-generation sequencing (NGS).

RESULTS

In total, 29 (55 %) of the patients were male, and the rate of dysgenesis was 19.2 %. In this study, 29 of 52 patients had at least one variant in one gene involved in CH (n = 29, 33 different variants) (Including likely benign variants and variants of unknown significance). There were 21 patients (40.3 %) with gland in situ. The most common variant was DUOX2 (20 %). The second most common variants were those in the TPO and TG genes (15 % and 15 %, respectively); 41.1 % of these were variants of uncertain significance (VUS), 26.4 % were pathogenic, 23.5 % were likely benign, and 11.7 % were likely pathogenic. On the basis of their zygosity, we identified 73.5 % heterozygous, 17.6 % homozygous, and 8.9 % combined heterozygous variants. There were mutant variants in two genes in six patients and three in one patient.

CONCLUSION

This study found a variant in 55 % of the patients and shed light on the etiology of some cases of CH. The frequency of VUS was high. Although variants were identified in this study, their implication in the etiology of CH is not certain and, for most of the patients, it is also not sufficient for explaining the pathology with the current state of knowledge.

Frequency of Mutations in the TPO Gene in Patients with Congenital Hypothyroidism Due to Dyshormonogenesis in Chile

Background and Objectives: Congenital thyroid dyshormonogenesis is caused by alterations in the synthesis of thyroid hormones in a newborn. Additionally, 10 to 20% of these cases are hereditary, caused by defects in proteins involved in hormonal synthesis. One of the most common causes is mutations in the thyroid peroxidase (TPO) enzyme gene, an autosomal recessive disease. We aimed to detect mutations of the TPO gene in 12 Chilean patients with congenital hypothyroidism due to dyshormonogenesis (CHD) and to characterize these patients clinically and molecularly. Materials and Methods: Twelve patients under 20 years of age with CHD, controlled at San Juan de Dios Hospital in Santiago, Chile, were selected according to the inclusion criteria: elevated neonatal TSH, persistent hypothyroidism, and thyroid normotopic by imaging study. Those with deafness, Down syndrome, and central or transient congenital hypothyroidism were excluded. Blood samples were taken for DNA extraction, and the 17 exons and exon-intron junctions of the TPO gene were amplified by PCR. The PCR products were sequenced by Sanger. Results: Two possibly pathogenic mutations of the TPO gene were detected: c.2242G>A (p.Val748Met) and c.1103C>T (p.Pro368Leu). These mutations were detected in 2 of 12 patients (16.6%): 1 was compound heterozygous c.1103C>T/c.2242G>A, and the other was heterozygous for c.2242G>A. In the diagnostic confirmation test, both patients presented diffuse hyper-uptake goiter on thyroid scintigraphy and high TSH in venous blood (>190 uIU/mL). Conclusions: The frequency of patients with possibly pathogenic mutations in TPO with CHD was 16.6%. Its study would allow for genetic counseling to be offered to the families of affected patients.

An insight into Indonesia's progress for newborn screening program: What is currently going on

Objectives

In this literature review, we describe the progress of Indonesia's NBS program (which is heavily centered on CH screening), its current pilot projects, and what lies ahead for this program.

Setting

Since its conception began with congenital hypothyroidism (CH) screening, Indonesia has experienced plodding progress in NBS. There is a shortage of literature discussing the history, or the lack of, and journey of NBS in Indonesia.

Methods

We searched for literature in Pubmed and Google Scholar with keywords such as "Newborn Screening, "Neonatal Screening," "Indonesia," "Asia Pacific," "Congenital Hypothyroidism," "Congenital Adrenal Hyperplasia,""Critical Congenital Heart Disease," "Hearing Loss," and "Inborn Error of Metabolism."

Results

The only mandatory and regulated NBS program in Indonesia is congenital hypothyroid (CH) screening, with some pilot projects being conducted on screening for congenital adrenal hyperplasia (CAH), critical congenital heart disease (CCHD), hearing loss, and to a lesser extent, inborn error of metabolisms (IEMs).

Conclusion

Despite the evidence and benefits, the government does not mandate or regulate newborn diseases such as CHD, CAH, hearing loss, and IEMs. The lack of regulation exists despite multiple pilot projects and studies showing a benefit in at least trying to screen newborns for those conditions.

Permanent vs Transient Congenital Hypothyroidism in Chinese Children: Physical Growth and Predictive Nomogram

CONTEXT

Few reliable markers are available to distinguish transient congenital hypothyroidism (TCH) and permanent congenital hypothyroidism (PCH). Additionally, the differences in growth between TCH and PCH remain unclear.

OBJECTIVE

To investigate the growth of children with TCH and PCH and develop a nomogram for early differentiation of these forms.

METHODS

This retrospective study included children with TCH or PCH. The predictive efficacy of the prognostic predictors was analyzed using receiver operating characteristic analysis. Multivariate prediction models were developed. Measurements of growth were compared between groups.

RESULTS

Patients with TCH had lower initial thyroid-stimulating hormone (TSH) than those with PCH at newborn screening (NBS). The supplementary dose of levothyroxine (L-T4) gradually decreased with age in TCH but not in PCH. The area under the curve (AUC) values of the initial TSH, L-T4 dose at 1 year of age, and L-T4 dose at 2 years of age for distinguishing TCH from PCH were 0.698, 0.71, and 0.879, respectively. The predictive efficacy of the multivariate models at 1 and 2 years of age improved, with AUC values of 0.752 and 0.922, respectively. A nomogram was built based on the multivariate model at 1 year of age. The growth did not differ between children with TCH and those with PCH. However, at 1 year of age, girls with CH exhibited higher z-scores in terms of height and weight than boys with CH.

CONCLUSION

TSH at NBS and L-T4 doses during treatment can be used to distinguish between PCH and TCH early in life, and the predictive efficacy can be improved using multivariable models with a visualized nomogram. At 3 years of age, patients with TCH and PCH showed similar growth.

Systematic review of thyroid function in NKX2-1-related disorders: Screening and diagnosis

BACKGROUND

NKX2-1-related disorders (NKX2-1-RD) are rare conditions affecting lung, thyroid, and brain development, primarily caused by pathogenic variants or deletions in the NKX2-1 gene. Congenital hypothyroidism (CH) is a common endocrine manifestation, leading to irreversible intellectual disability if left untreated.

OBJECTIVES

The aim was to evaluate the current evidence for the use of screening and diagnostic techniques for endocrine alterations in patients with NKX2-1-RD.

METHODS

This systematic review was reported following the PRISMA guidelines. Two separate research questions in PICO format were addressed to cover initial screening and diagnosis procedures for endocrine diseases in patients with NKX2-1-RD. Eligibility criteria focused on patients with genetic confirmation of the disease and hypothyroidism. Various databases were searched, and data were extracted and assessed independently by two reviewers.

RESULTS

Out of 1012 potentially relevant studies, 46 were included, for a total of 113 patients. CH was the most frequent endocrine alteration (45% of patients). Neonatal screening was reported in only 21% of patients based on blood TSH measurements. TSH thresholds varied widely across studies, making hypothyroidism detection ranges difficult to establish. Diagnostic tests using serum TSH were used to diagnose hypothyroidism or confirm its presence. 35% of patients were diagnosed at neonatal age, and 42% at adult age. Other hormonal dysfunctions identified due to clinical signs, such as anterior pituitary deficiencies, were detected later in life. Thyroid scintigraphy and ultrasonography allowed for the description of the thyroid gland in 30% of cases of hypothyroidism. Phenotypic variability was observed in individuals with the same variants, making genotype-phenotype correlations challenging.

CONCLUSION

This review highlights the need for standardized protocols in endocrine screening for NKX2-1-RD, emphasizing the importance of consistent methodology and hormone threshold levels. Variability in NKX2-1 gene variants further complicates diagnostic efforts. Future research should concentrate on optimizing early screening protocols and diagnostic strategies.

Clinical and molecular study of patients with thyroid dyshormogenesis and variants in the thyroglobulin gene

Introduction

Defects in any thyroid hormone synthesis steps cause thyroid dyshormonogenesis (THD). THD due to thyroglobulin (TG) gene variants is a cause of congenital hypothyroidism (CH) with a wide clinical spectrum, ranging from mild to severe permanent hypothyroidism. We present high-throughput sequencing results of patients with TG variants.

Methods

A CH high-throughput sequencing-panel of the main genes involved in the regulation of thyroid hormonogenesis was performed to identify those TG variants that may be related to patient THD phenotype.

Results

We identified 21 TG gene variants in 19 patients (11.8%) which could explain their phenotype. Ten of those (47.6%) were not previously described. CH was biochemically severe in these 19 patients. Eight of them were reevaluated after one month of discontinuing LT4 treatment and all had severe permanent hypothyroidism. We also identified another 16 patients who presented heterozygous TG variants, of whom, at reevaluation, five had mild permanent and only one had severe permanent hypothyroidisms.

Discussions

In this study, 10 novel and 11 previously reported variants in the TG gene have been identified that could explain the phenotype of 19 patients from non-consanguineous families from a large THD cohort. Although not all these TG gene variants can explain all the patients' THD phenotypes, some of them had severe or mild permanent hypothyroidism at reevaluation.

Late gestation fetal hypothyroidism alters cell cycle regulation across multiple organ systems

BACKGROUND

Hypothyroidism is a common endocrine disruption observed in utero that adversely affects fetal growth and maturation leading to long-term impacts on health; however, the exact molecular mechanisms by which these deleterious effects occur are unknown. We hypothesize that fetal hypothyroidism during late gestation will disrupt cell cycle regulation in a tissue-specific manner. To evaluate this, eight pregnant gilts were dosed with either methimazole or an equivalent negative control during days 85-106 out of 114 days of gestation (n = 4/group). Following treatment, the gilts were humanely euthanized, and tissue samples of fetal heart, ileum, kidney, lung, liver, muscle, spleen, and thymus taken from two male and two female fetuses (n = 32) from each gilt.

RESULTS

The relative expression of three cell cycle promoters (CDK1, CDK2, and CDK4), and one cell cycle inhibitor (CDKN1A) was compared in each tissue to determine the effect of hypothyroidism on the developing fetus. All of the eight tissues examined experienced at least one significant up- or downregulation in the expression of the aforementioned genes as a result of treatment with methimazole. Substantial changes were observed in the liver and muscle, with the latter experiencing significant downregulations of CDK1, CDK2, and CDK4 as a result of treatment. In addition, all tissues were examined for changes in protein content, which further elucidated the impact of hypothyroidism on the fetal liver by the observation of a marked increase in protein content in the methimazole-treated group. Finally, the heart and liver were histologically examined for evidence of cellular hyperplasia and hypertrophy by measuring average nuclei density and size in each tissue, with the results showing a significant decrease in average nuclei size in the liver of hypothyroid fetuses.

CONCLUSIONS

Collectively, these findings indicate the occurrence of organ-specific disruptions in cell cycle progression as a result of in utero hypothyroidism, which may explain the long term and widespread effects of hypothyroidism on fetal development.

Increased thyroid stimulating hormone (TSH) as a possible risk factor for atherosclerosis in subclinical hypothyroidism

Primary hypothyroidism (PHT) is associated with an increased risk for the development of atherosclerosis (AS) and other cardiovascular disorders. PHT induces atherosclerosis (AS) through the induction of endothelial dysfunction, and insulin resistance (IR). PHT promotes vasoconstriction and the development of hypertension. However, patients with subclinical PHT with normal thyroid hormones (THs) are also at risk for cardiovascular complications. In subclinical PHT, increasing thyroid stimulating hormone (TSH) levels could be one of the causative factors intricate in the progression of cardiovascular complications including AS. Nevertheless, the mechanistic role of PHT in AS has not been fully clarified in relation to increased TSH. Therefore, in this review, we discuss the association between increased TSH and AS, and how increased TSH may be involved in the pathogenesis of AS. In addition, we also discuss how L-thyroxine treatment affects the development of AS.

Unusual congenital goiter due to maternal Hashimoto thyroiditis: a case report

Congenital hypothyroidism (CH) is the most common cause of endocrinopathy in the newborn Its incidence lies between 1 in 3,000 and 1 in 2,000, However, congenital goiter is a rare form of presentation. Hypothyroidism secondary to autoimmune etiology is extremely rare, with an incidence of 1:84.700-1:31.000 newborns. Anti-thyroid peroxidase antibodies (TPOAb) are able to cross the placenta but rarely induce hypothyroidism in the newborn, much less goiter. A case of congenital goiter in a male newborn secondary to maternal high TPOAb levels is reported. The mother was diagnosed of Hashimoto thyroiditis prior to the pregnancy. At birth, a grade 3 goiter was detected in the newborn. Laboratory testings revealed hypothyroidism with free thyroxine of 7.6 pmol/L, thyroid-stimulating hormone of 108 mUI/L and high TPOAb levels. Treatment with Levothyroxine was started the second day of life with progressive thyroid function normalization. Neurological development has been normal until the date.

Clinical and magnetic resonance imaging findings in a French bulldog puppy with genetically confirmed congenital hypothyroidism

A 7-month-old male French bulldog was referred for abnormal mentation and gait. Physical examination revealed a dome shaped calvarium and persistent bregmatic fontanelle. Neurological examination revealed proprioceptive ataxia, pelvic limb paraparesis and strabismus with moderate ventriculomegaly, thinning of the cerebral parenchyma, and widened cerebral sulci on magnetic resonance imaging. Masses were identified in the region of the thyroid, which appeared heterogeneous and hyperintense in T1-weighted and T2-weighted compared with the adjacent muscle signal masses were identified. Radiological diagnosis was hydrocephalus "ex vacuo" and goiter. Blood test revealed abnormally low total thyroxine (TT4), free thyroxine (FT4), and normal thyrotropin concentration. A diagnosis of congenital hypothyroidism was confirmed by positive genetic test for thyroid peroxidase mutation. Thyroxine supplementation treatment rapidly improved clinical signs.

Hypothyroidism in Patients with Down Syndrome: Prevalence and Association with Congenital Heart Defects

This population-based study aimed to assess the prevalence of congenital hypothyroidism (CH) and overt hypothyroidism (OH) and their association with congenital heart defects (CHDs) in patients with Down syndrome (DS). The population included all live births residing in Tuscany (Italy) diagnosed with DS recorded in the Registry of Congenital Defects and in the Registry of Rare Diseases of Tuscany in the years 2003-2017. The prevalence of CH and OH in DS patients was calculated by sex and by period. The association of CH and OH with CHDs in DS patients was assessed using multivariate logistic regression. The cohort included 228 subjects. The prevalence of CH and OH was 11.4% (95%CI: 7.4-16.7%) and 12.7% (95%CI: 8.5-12.3%), respectively, with no significant difference by sex. A significant increase in the prevalence of CH (p < 0.0001) was found in the years 2010-2017 compared to the previous period, and among preterm infants (p = 0.009). The presence of CH was associated with a higher prevalence of CHDs (adjusted OR = 2.24, p = 0.082). A significant association between ventricular septal defects (VSDs) and the occurrence of OH (adjusted OR = 3.07, p = 0.025) was also observed. This study confirmed the higher prevalence of both CH and OH in DS compared to the general population. Furthermore, the risk of association between DS and CHDs was higher in the presence of CH, while VSDs are associated with OH, providing relevant insights into the epidemiology of hypothyroidism in DS and associated anomalies.

An Integrative/Functional Approach to Congenital Hypothyroidism in Infants

Congenital hypothyroidism (CHT) is a condition that, if left untreated, has severe consequences. In this case we report the resolution of hypothyroidism in a newborn with nutritional and alternative treatments. In evidence-based medicine, clinical expertise, research, and patient preference are an important triad used to make clinical decisions; in this case the patient's parents preferred to begin with nutritional and alternative treatments.

Correlation between systemic inflammatory response index and thyroid function: 2009-2012 NHANES results

Aims

This study investigates the relationship between the Systemic Inflammatory Response Index (SIRI) and thyroid function.

Methods

Utilizing data from the National Health and Nutrition Examination Survey (NHANES) 2009-2012, we excluded participants lacking SIRI or thyroid function data, those under 20 years, and pregnant individuals. SIRI was determined using blood samples. We conducted weighted multivariate regression and subgroup analyses to discern the independent relationship between SIRI and thyroid function.

Results

The study included 1,641 subjects, with an average age of 47.26±16.77 years, including 48.65% males and 51.35% females. The population was divided into three SIRI-based groups (Q1-Q3). Q3, compared to Q1, exhibited higher age-at-onset, greater male prevalence, and increased levels of FT3, FT4, TT4, leukocytes, and triglycerides. This group also showed a higher incidence of diabetes, hypertension, and smoking. Notably, Q1 had lower LDL and HDL levels. SIRI maintained a positive association with FT4 (β = 0.01, 95% CI = 0.00-0.03, P for trend = 0.0071), TT4 (β = 0.20, 95% CI = 0.10, 0.31, P for trend=0.0001), and TPOAb (β = 8.0, 95% CI = 1.77-14.30, P for trend = 0.0120), indicating that each quartile increase in SIRI corresponded to a 0.01 ng/dL increase in FT4, a 0.2 g/dL increase in TT4, and an 8.03 IU/mL rise in TPOAb. The subgroup analysis suggested the SIRI-thyroid function correlation was influenced by hypertension.

Conclusion

Inflammation may impact the development and progression of thyroid function disorders. Proactive anti-inflammatory treatment might mitigate thyroid abnormalities.

Thyroid hormone biosynthesis and its role in brain development and maintenance

Thyroid hormones are critical modulators in the physiological processes necessary to virtually all tissues, with exceptionally fundamental roles in brain development and maintenance. These hormones regulate essential neurodevelopment events, including neuronal migration, synaptogenesis, and myelination. Additionally, thyroid hormones are crucial for maintaining brain homeostasis and cognitive function in adulthood. This chapter aims to offer a comprehensive understanding of thyroid hormone biosynthesis and its intricate role in brain physiology. Here, we described the mechanisms underlying the biosynthesis of thyroid hormones, their influence on various aspects of brain development and ongoing maintenance, and the proteins in the brain that are responsive to these hormones. This chapter was geared towards broadening our understanding of thyroid hormone action in the brain, shedding light on potential therapeutic targets for neurodevelopmental and neurodegenerative disorders.

Evaluation of patients diagnosed with congenital hypothyroidism by newborn screening between 2011-2019 in Diyarbakir, Turkey

This study aimed to determine the incidence of congenital hypothyroidism in Turkey's Diyarbakir Province and assess the development and growth conditions of people with congenital hypothyroidism. Patients born between 2011-2019 and diagnosed with congenital hypothyroidism within the scope of the newborn screening program were included. The medical records of these patients were retrospectively reviewed. The length and weight for age, weight for length, and body mass index standard deviation scores were calculated. We investigated the treatment status of the patients, whether their relatives had a similar disorder, and the presence of consanguinity between parents. Blood samples were collected from 380,592 newborns. As a result of further tests, 498 newborns were diagnosed with congenital hypothyroidism (incidence: 1/764). Demographic and anthropometric data of 241 patients were analyzed. The patients comprised 46.9% (n = 113) females and 53.1% (n = 128) males. It was determined that 44.4% of the individuals had transient congenital hypothyroidism and 53.6% had permanent congenital hypothyroidism. The parents of 29.8% of the individuals diagnosed with transient congenital hypothyroidism and 44.2% of the individuals diagnosed with permanent congenital hypothyroidism were consanguineous (P = .02). According to the latest anthropometric assessment, 6.8% of individuals diagnosed with congenital hypothyroidism had a weight z-score below -2 SD and 16.9% had a length z-score below -2 SD. The incidence of congenital hypothyroidism was higher in our region. The ratio of consanguinity between parents was higher in patients diagnosed with permanent congenital hypothyroidism than in those diagnosed with transient congenital hypothyroidism. According to the most recent follow-up, weight and age were found to be similar in patients with transient and permanent congenital hypothyroidism.

Normal intellectual ability and hyperprolactinemia as unique clinical manifestations of congenital hypothyroidism: A case report and review of hypotheses

Congenital hypothyroidism is the deficiency of thyroid hormone in infants and hyperprolactinemia is frequently observed. Previously reported cases typically involve intellectual disability, highlighting this particular unique case report to the first reported patient demonstrating normal intellectual ability despite experiencing growth and gonad dysfunction. This study aims to present a case and review medical hypotheses related to the patient's condition. A 19-year-old female presented with a chief complaint of irregular menstruation for up to 40 days or not occurring at all. The patient experienced the first menstruation at the age of 16 years old. The patient's height was 133 cm, body weight 40 kg, and body mass index 22.61 kg/m2; other family members were normal. Physical examination showed no abnormalities, and laboratory examination showed suppressed serum free T4 (FT4) level (6.41 pmol/L), elevated thyroid stimulating hormone (TSH) level (333.700 µIU/mL), and elevated prolactin hormone level (32.03 ng/mL). Ultrasound of the thyroid gland found hypoplasia of the left and right thyroid glands. The patient was a college student enrolled in a public national university and had never complained about academic performance throughout the patient's education. The patient was diagnosed with congenital hypothyroidism and hyperprolactinemia. The patient was administered up to 100 µg daily of oral levothyroxine, which improved the patient's menstrual cycles. The patient's delayed diagnosis may be attributed to central congenital hypothyroidism being underdiagnosed. We hypothesized that thyroid-releasing hormone receptor (TRHR) gene mutation might contribute to the underlying cause of hyperprolactinemia and normal intellectual ability of the patient. Further study on the significance of TRHR gene mutations in congenital hypothyroidism is required to improve diagnosis and treatment.

Optimizing the Dutch newborn screening for congenital hypothyroidism by incorporating amino acids and acylcarnitines in a machine learning-based model

Objective

Congenital hypothyroidism (CH) is an inborn thyroid hormone (TH) deficiency mostly caused by thyroidal (primary CH) or hypothalamic/pituitary (central CH) disturbances. Most CH newborn screening (NBS) programs are thyroid-stimulating-hormone (TSH) based, thereby only detecting primary CH. The Dutch NBS is based on measuring total thyroxine (T4) from dried blood spots, aiming to detect primary and central CH at the cost of more false-positive referrals (FPRs) (positive predictive value (PPV) of 21% in 2007-2017). An artificial PPV of 26% was yielded when using a machine learning-based model on the adjusted dataset described based on the Dutch CH NBS. Recently, amino acids (AAs) and acylcarnitines (ACs) have been shown to be associated with TH concentration. We therefore aimed to investigate whether AAs and ACs measured during NBS can contribute to better performance of the CH screening in the Netherlands by using a revised machine learning-based model.

Methods

Dutch NBS data between 2007 and 2017 (CH screening results, AAs and ACs) from 1079 FPRs, 515 newborns with primary (431) and central CH (84) and data from 1842 healthy controls were used. A random forest model including these data was developed.

Results

The random forest model with an artificial sensitivity of 100% yielded a PPV of 48% and AUROC of 0.99. Besides T4 and TSH, tyrosine, and succinylacetone were the main parameters contributing to the model's performance.

Conclusions

The PPV improved significantly (26-48%) by adding several AAs and ACs to our machine learning-based model, suggesting that adding these parameters benefits the current algorithm.

Assessment of Neurodevelopment and Growth in Congenital Hypothyroidism: Serial 6-Year Follow-up Study of 408 Patients

CONTEXT

The link between congenital hypothyroidism (CH) and neurodevelopment is suggested, yet studies applying quantifiable measures are lacking. Moreover, socioeconomic disparities and subtle variation in timing of approach make the relationship difficult to detect.

OBJECTIVE

To evaluate associations between CH and abnormalities in neurodevelopment and growth and determine the critical period for intervention.

METHODS

We utilized a nationwide database to conduct a longitudinal analysis of 919 707 children. Exposure to CH was identified using claims-based data. The primary outcome of interest was suspected neurodevelopmental disorder, as measured using the Korean Ages & Stages Questionnaires (K-ASQ) administered annually from 9 to 72 months of age. Secondary outcomes were height and BMI z-scores. After randomly matching cases and controls at a 1:10 ratio, we employed inverse probability of treatment weighting and generalized estimating equation models for our analyses. We conducted subgroup analysis based on the age of treatment initiation.

RESULTS

The prevalence of CH in our population was 0.05% (n = 408). Relative to the control group, the CH group had higher risk of suspected neurodevelopmental disorders (propensity score-weighted odds ratio: 4.52; 95% CI: 2.91, 7.02), and significantly increased risk in each of the 5 K-ASQ domains. No time interactions were noted at any rounds for the outcomes according to when the neurodevelopmental assessment was conducted (all P for interaction >.05). The CH group also had higher risk for low height-for-age z-score, but not for elevated BMI-for-age z-score. In subgroup analysis, delayed medication for CH correlated with worse neurodevelopmental outcomes.

CONCLUSION

The CH group had worse neurodevelopmental outcomes and reduced height-for-age z-score. Outcomes were worse when onset of treatment was increasingly delayed.

Effects of low-dose levothyroxine on atrial natriuretic peptide and c-type natriuretic peptide in children with neonatal hypothyroidism

OBJECTIVE

This study was designed to explore the effects of low-dose levothyroxine (LT4) on levels of atrial natriuretic peptide (ANP) and c-type natriuretic peptide (CNP) in neonates with hypothyroidism (NH).

METHODS

In this retrospective study, a total of 90 cases of NH screened out and confirmed by the First Affiliated Hospital of Zhejiang Chinese Medical University from October 2014 to February 2018 were selected as a study group. 80 healthy children who underwent physical examination during the same time period were enrolled as controls. Before and after treatment with LT4, the changes in the levels of serum thyroid stimulating hormone (TSH) and free thyroxine (FT4) were observed, and the changes in the levels of ANP and CNP and their relationships to clinical efficacy were evaluated. Additionally, the growth and development of body and the scores of the China-Wechsler Younger Children Scale of Intelligence (C-WYCSI) were compared before and after the treatment, and the changes in the cardiac functions of children in the study group were evaluated. Independent risk factors for mental abnormality after treatment were analyzed by logistic regression.

RESULTS

After treatment, TSH levels in patients declined, while the levels of T3, T4, free triiodothyronine (FT3), and FT4 increased, without significant differences between groups. After treatment, ANP levels in patients increased but CNP levels decreased. ANP levels were negatively correlated with clinical efficacy, but CNP levels were positively correlated with it. Ultrasonic cardiography showed the improved cardiac functions. After treatment, the growth and development of body and the C-WYCSI scores increased compared to those before treatment. First visit date, T3, FT4, TSH were independent risk factors for mental disorders in children.

CONCLUSION

For children with NH, low-dose LT4 can correct the level of thyroid function, promote physical and mental development, and improve the levels of ANP and CNP.

Increased incidence of congenital hypothyroidism in China: An analysis of 119 million screened newborns

Despite the lack of nationwide epidemiological studies, congenital hypothyroidism (CH) incidence in China has increased. We aimed to evaluate the trends of CH and the possible reasons behind them. Data from screened newborns from the Chinese Newborn Screening Information System from 2012 to 2019 was collected. We applied the Bayesian hierarchical Poisson regression model and meta-analysis to estimate incidence or proportion over the years. The estimated CH incidence increased from 4.01 per 10,000 births in 2012 to 5.77 per 10,000 births in 2019. The average annual growth rate (ARG) of CH incidence for all provinces varied from 0.59 to 20.96%. The most rapid rise in incidence was observed in cases with an initial thyroid stimulating hormone (TSH) concentration of < 10 mIU/L. The meta-analysis results showed that the proportion of permanent CH increased by 0.024% (95%CI: 0.011%, 0.037%) annually. Each 1 mIU/L decrease in TSH cutoff value was associated with a 2.96% increase in CH incidence. In the same period, the proportion of premature CH cases increased from 6.60 to 9.10%, which was much higher than the increase in preterm births. A significant relationship was not found between provincial growth rates in screening coverage and provincial baseline incidences of CH.  Conclusion: CH incidence has substantially increased in China. The slight adjustment of the TSH cutoff value and increasing preterm birth rate contribute to such a trend; however, the contribution is limited. What is Known: • An uptrend in congenital hypothyroidism (CH) incidence has been reported in many European and American countries in the last two decades; however, no studies have been conducted in China to explain the increased CH incidence. • We provide a detailed epidemiological report on the trends of CH during 2012-2019 in China, with an attempt to explore the reasons behind it. What is New: • This first-ever national-wide epidemiological report in China showed an uptrend in CH incidence with variations over regions and CH subtypes. The mild lowering of TSH cutoff values and the increasing preterm birth rate contributed to this uptrend.

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.

Uncovering Congenital Hypothyroidism in Adulthood: A Case Study Emphasizing the Urgency of Screening and Clinical Awareness

Congenital hypothyroidism (CH) is an endocrine disorder primarily diagnosed during the neonatal period through routine screening. Screening programs have been established in most developed countries. However, routine neonatal screening is not available in India, and the mainstay for diagnosis is clinical awareness. In this report, we present a case of CH diagnosed for the first time in a 20-year-old male who sought medical attention at our hospital's emergency department due to fever and altered sensorium. This case report elucidates the implications of a delayed diagnosis of CH, shedding light on the pivotal role of neonatal screening and the need for enhanced awareness within the healthcare community and among families.

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.

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.

Machine learning to improve false-positive results in the Dutch newborn screening for congenital hypothyroidism

OBJECTIVE

The Dutch Congenital hypothyroidism (CH) Newborn Screening (NBS) algorithm for thyroidal and central congenital hypothyroidism (CH-T and CH-C, respectively) is primarily based on determination of thyroxine (T4) concentrations in dried blood spots, followed by thyroid-stimulating hormone (TSH) and thyroxine-binding globulin (TBG) measurements enabling detection of both CH-T and CH-C, with a positive predictive value (PPV) of 21%. A calculated T4/TBG ratio serves as an indirect measure for free T4. The aim of this study is to investigate whether machine learning techniques can help to improve the PPV of the algorithm without missing the positive cases that should have been detected with the current algorithm.

DESIGN & METHODS

NBS data and parameters of CH patients and false-positive referrals in the period 2007-2017 and of a healthy reference population were included in the study. A random forest model was trained and tested using a stratified split and improved using synthetic minority oversampling technique (SMOTE). NBS data of 4668 newborns were included, containing 458 CH-T and 82 CH-C patients, 2332 false-positive referrals and 1670 healthy newborns.

RESULTS

Variables determining identification of CH were (in order of importance) TSH, T4/TBG ratio, gestational age, TBG, T4 and age at NBS sampling. In a Receiver-Operating Characteristic (ROC) analysis on the test set, current sensitivity could be maintained, while increasing the PPV to 26%.

CONCLUSIONS

Machine learning techniques have the potential to improve the PPV of the Dutch CH NBS. However, improved detection of currently missed cases is only possible with new, better predictors of especially CH-C and a better registration and inclusion of these cases in future models.

Neonatal reference intervals for thyroid stimulating hormone and free thyroxine assayed on a Siemens Atellica® IM analyzer: a cross sectional study

BACKGROUND

Deriving population specific reference intervals (RIs) or at the very least verifying any RI before adoption is good laboratory practice. Siemens has provided RIs for thyroid stimulating hormone (TSH) and free thyroxine (FT4) determined on their Atellica® IM analyzer for all age groups except the neonatal age group which provides a challenge for laboratories that intend to use it to screen for congenital hypothyroidism (CH) and other thyroid disorders in neonates. We set out to determine RIs for TSH and FT4 using data obtained from neonates undergoing routine screening for CH at the Aga Khan University Hospital, Nairobi, Kenya.

METHODOLOGY

TSH and FT4 data for neonates aged 30 days and below were extracted from the hospital management information system for the period March 2020 to June 2021. A single episode of testing for the same neonate was included provided both TSH and FT4 were done on the same sample. RI determination was performed using a non-parametric approach.

RESULTS

A total of 1243 testing episodes from 1218 neonates had both TSH and FT4 results. A single set of test results from each neonate was used to derive RIs. Both TSH and FT4 declined with increase in age with a more marked decline seen in the first 7 days of life. There was a positive correlation between logFT4 and logTSH (r_s (1216) = 0.189, p = < 0.001). We derived TSH RIs for the age groups 2-4 days (0.403-7.942 µIU/mL) and 5-7 days (0.418-6.319 µIU/mL), and sex specific RIs for males (0.609-7.557 µIU/mL) and females (0.420-6.189 µIU/mL) aged 8-30 days. For FT4, separate RIs were derived for the age groups 2-4 days (1.19-2.59 ng/dL), 5-7 days (1.21-2.29 ng/dL) and 8-30 days (1.02-2.01 ng/dL).

CONCLUSION

Our neonatal RIs for TSH and FT4 are different from those published or recommended by Siemens. The RIs will serve as a guide for the interpretation of thyroid function tests in neonates from sub-Saharan Africa where routine screening for congenital hypothyroidism using serum samples is done on the Siemens Atellica® IM analyzer.

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.

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.

Iodine and Thyroid Maternal and Fetal Metabolism during Pregnancy

Thyroid hormones and iodine are required to increase basal metabolic rate and to regulate protein synthesis, long bone growth and neuronal maturation. They are also essential for protein, fat and carbohydrate metabolism regulation. Imbalances in thyroid and iodine metabolism can negatively affect these vital functions. Pregnant women are at risk of hypo or hyperthyroidism, in relation to or regardless of their medical history, with potential dramatic outcomes. Fetal development highly relies on thyroid and iodine metabolism and can be compromised if they malfunction. As the interface between the fetus and the mother, the placenta plays a crucial role in thyroid and iodine metabolism during pregnancy. This narrative review aims to provide an update on current knowledge of thyroid and iodine metabolism in normal and pathological pregnancies. After a brief description of general thyroid and iodine metabolism, their main modifications during normal pregnancies and the placental molecular actors are described. We then discuss the most frequent pathologies to illustrate the upmost importance of iodine and thyroid for both the mother and the fetus.

Global prevalence of congenital hypothyroidism among neonates from 1969 to 2020: a systematic review and meta-analysis

Little is known about the global prevalence of congenital hypothyroidism (CH), though it is known to vary across countries and time periods. This meta-analysis aims to estimate the global and regional prevalence of CH among births between 1969 and 2020. PubMed, Web of Sciences, and Embase databases were searched for relevant studies between January 1, 1975, and March 2, 2020. Pooled prevalence was calculated using a generalized linear mixed model, and expressed as a rate per 10,000 neonates. The meta-analysis involved 116 studies, which analyzed 330,210,785 neonates, among whom 174,543 were diagnosed with CH. The pooled global prevalence of CH from 1969 to 2020 was 4.25 (95% confidence interval (CI) 3.96-4.57). The geographic region with highest prevalence was the Eastern Mediterranean (7.91, 95% CI 6.09-10.26), where the prevalence was 2.48-fold (95% CI 2.04-3.01) that in Europe. The national income level with the highest prevalence was upper-middle (6.76, 95% CI 5.66-8.06), which was 1.91-fold (95% CI 1.65-2.22) that in high-income countries. Global prevalence of CH was 52% (95% CI 4-122%) higher in 2011-2020 than in 1969-1980, after adjusting for geographic region, national income level, and screening strategy.  Conclusion: The global prevalence of CH increased from 1969 to 2020, which may reflect the implementation of national neonatal screening, neonatal testing for thyroid-stimulating hormone, and a lowering of the diagnostic level of this hormone. Additional factors are likely to be driving the increase, which should be identified in future research. What is Known: • Cumulated evidence had suggested that the occurrences of congenital hypothyroidism (CH) among newborns were varied in different countries.. • Up-trends of the birth prevalence of CH were observed in many European and American countries. What is New: • This is the first meta-analysis to estimate global and regional prevalence of CH among newborns. • The global prevalence of CH has increased by 127% since 1969. The Eastern Mediterranean has the highest prevalence and stands out with the most pronounced escalation in the prevalence of CH.

Congenital hypothyroidism: a case report of an Egyptian child with congenital heart disease, pelvic kidney and cavernous transformation of portal vein

Background

A case of thyroid hormone deficiency which presented at birth. Thyroid hormones are essential for brain development and normal cognitive function. Common symptoms of congenital hypothyroidism (CH) include constipation, decreased activity, increased sleep and feeding difficulty. Common signs include dry skin, macroglossia and umbilical hernia. If congenital hypothyroidism is left untreated after birth, it can lead to permanent intellectual disability and growth failure.

Case presentation.

Here, we report a 10.5-year-old female with the typical features of CH. She is the sixth in order of birth of consanguineous Egyptian parents. No family history of similar condition. Our patient had primary CH caused by thyroid agenesis. She had congenital heart disease, pelvic kidney, cavernous transformation of portal vein and parenchymatous liver disease.

Conclusions

Congenital hypothyroidism is associated with an elevated risk of congenital anomalies. Clinical suspicion of symptoms and signs of congenital hypothyroidism are important for early diagnosis and prevention of serious problems that are related to congenital hypothyroidism.

Adult Thyroid Outcomes of Congenital Hypothyroidism

BACKGROUND

More than 40 years have passed since the introduction of newborn screening for congenital hypothyroidism (CH), and many early diagnosed patients have reached adulthood. Their thyroid morphology and function have been little studied. This cross-sectional, observational study was conducted to characterize the thyroid morphology and function of adult CH patients diagnosed in the framework of newborn screening for CH.

METHODS

A total of 103 adult CH patients born after 1979 were enrolled at Ito Hospital, Tokyo, Japan, and were classified into Goiter, Normal gland, and Dysgenesis groups based on ultrasonographic findings. For 60 patients, genetic analysis was performed. Thyroid function test results and the proportion of patients with thyroid nodules were compared among the three groups and between 56 female CH patients and 168 non-CH women matched for TSH levels.

RESULTS

A significantly low serum free T3/free T4 ratio (0.22) was observed in the Dysgenesis group. Thyroid nodules were detected in 14.3% (8/56) of female CH patients, more frequently than in non-CH women. Thyroid nodules were detected the most frequently in the Goiter group (71%, 10/14). Genetic defects were identified in 89% (8/9) of patients belonging to the Goiter group, including thyroglobulin defect (33%, 3/9), thyroid peroxidase defect (33%, 3/9), and dual oxidase 2 defect (22%, 2/9).

CONCLUSIONS

Our results suggest that adults with thyroid dysgenesis on levothyroxine replacement therapy have relative T3 deficiency. Most adults with goitrous CH have genetic dyshormonogenesis. They are at high risk of developing thyroid nodules. Our findings support the current guideline recommendation that CH patients with dyshormonogenesis should undergo periodic thyroid ultrasonography.

Prevalence of Transient Hypothyroidism in Children Diagnosed with Congenital Hypothyroidism between 2000 and 2016

Newborn screening (NBS) for congenital hypothyroidism (CH) was introduced in Switzerland in 1977, which allowed for the preclinical, biochemical diagnosis. The aim of this study was to evaluate the prevalence of transient CH (tCH) in the canton of Zurich. In this analytical cohort study, all newborns born in the canton of Zurich, between the 1st of January 2000 and the 30st of June 2016, with a TSH value above 15 mU/L (whole blood) were included. There were 115 cases out of 247,918 babies born during the study period. However, 23 cases had to be excluded due to missing data. The definite diagnosis was made after a thyroxine withdrawal at 2 years of age. The total prevalence of confirmed CH and the female to male ratio (f/m) were 1:2695 and 2.17:1; for permanent CH (pCH), 1:3443 and 2.8:1; and for tCH, 1:12,396 and 1:1, respectively. The TSH value was significantly higher in pCH compared to tCH, at 130.3 (62.9-171.9) and 36.4 (26.5-53.3) (median and interquartile range), respectively (p < 0.001). The prevalences found for congenital hypothyroidism and its transient form are comparable to previous studies. TSH concentration at birth was predictive for the further course of the disease. Low birth weight correlated with a tCH, whereas low gestational age did not. The dominance of the female sex in congenital hypothyroidism is supported by a gender ratio of 2.17:1.

Clinical and genetic investigation in patients with permanent congenital hypothyroidism

BACKGROUND

Permanent congenital hypothyroidism (CH) is usually a more severe type of CH. However, the molecular etiology and clinical features of permanent CH remain unclear.

METHODS

We recruited 42 patients who were diagnosed with CH and followed-up after diagnosis. Demographic information and data at diagnosis and treatment were recorded. Genetic analyses were performed using whole exome sequencing. Based on the presence or absence of variants and differences in clinical features, we grouped the study participants and analyzed their characteristics.

RESULTS

A total of 29 patients (69.0 %) were identified as having variants potentially related to their disease. Among the 24 patients with normal-sized thyroid gland-in-situ (GIS) or goiter, 23 (95.8 %, P < 0.001) had variants. This is compared to 18 patients with thyroid dysgenesis (TD), of which six (33.3 %) had genetic variants. We detected 55 variants in six genes, the most frequently mutated gene being DUOX2 (70.9 %). Biallelic DUOX2 variants were detected in 14 of 24 (58.3 %) GIS or goiter patients. Compared to the cases with variants, the L-T4 dose at 2 and 3 years of age and current dose were higher in the unmutated cases. At 2 years of age, patients with TD required higher doses of L-T4 supplementation. Patients with DUOX2 variants showed lower doses of L-T4 being required at 2 and 3 years of age and current. Furthermore, patients with GIS or goiter with DUOX2 variants showed lower doses of L-T4.

CONCLUSIONS

Patients with CH, whether TD or GIS or goiter, are at risk of developing a permanent condition. Compared with patients with TD, the detection of variants was higher in patients with GIS or goiter. The most frequently mutated gene was DUOX2, with a biallelic type. Patients with TD required higher doses of L-T4 supplementation with age, whereas those patients with the DUOX2 variant required relatively lower doses.

Congenital Hypothyroidism: Screening and Management

ABSTRACT

Untreated congenital hypothyroidism (CH) leads to intellectual disabilities. Prompt diagnosis by newborn screening (NBS) leading to early and adequate treatment results in grossly normal neurocognitive outcomes in adulthood. However, NBS for hypothyroidism is not yet established in all countries globally. Seventy percent of neonates worldwide do not undergo NBS.The initial treatment of CH is levothyroxine, 10 to 15 mcg/kg daily. The goals of treatment are to maintain consistent euthyroidism with normal thyroid-stimulating hormone and free thyroxine in the upper half of the age-specific reference range during the first 3 years of life. Controversy remains regarding detection of thyroid dysfunction and optimal management of special populations, including preterm or low-birth weight infants and infants with transient or mild CH, trisomy 21, or central hypothyroidism.Newborn screening alone is not sufficient to prevent adverse outcomes from CH in a pediatric population. In addition to NBS, the management of CH requires timely confirmation of the diagnosis, accurate interpretation of thyroid function testing, effective treatment, and consistent follow-up. Physicians need to consider hypothyroidism in the face of clinical symptoms, even if NBS thyroid test results are normal. When clinical symptoms and signs of hypothyroidism are present (such as large posterior fontanelle, large tongue, umbilical hernia, prolonged jaundice, constipation, lethargy, and/or hypothermia), measurement of serum thyroid-stimulating hormone and free thyroxine is indicated, regardless of NBS results.

Congenital Hypothyroidism: Screening and Management

Untreated congenital hypothyroidism (CH) leads to intellectual disabilities. Newborn screening (NBS) for CH should be performed in all infants. Prompt diagnosis by NBS leading to early and adequate treatment results in grossly normal neurocognitive outcomes in adulthood. However, NBS for hypothyroidism is not yet practiced in all countries globally. Seventy percent of neonates worldwide do not undergo NBS. The recommended initial treatment of CH is levothyroxine, 10 to 15 mcg/kg daily. The goals of treatment are to maintain consistent euthyroidism with normal thyroid-stimulating hormone and with free thyroxine in the upper half of the age-specific reference range during the first 3 years of life. Controversy remains regarding the detection of thyroid dysfunction and optimal management of special populations, including preterm or low-birth-weight infants and infants with transient or mild CH, trisomy 21, or central hypothyroidism. NBS alone is not sufficient to prevent adverse outcomes from CH in a pediatric population. In addition to NBS, the management of CH requires timely confirmation of the diagnosis, accurate interpretation of thyroid function testing, effective treatment, and consistent follow-up. Physicians need to consider hypothyroidism in the face of clinical symptoms, even if NBS thyroid test results are normal. When clinical symptoms and signs of hypothyroidism are present (such as large posterior fontanelle, large tongue, umbilical hernia, prolonged jaundice, constipation, lethargy, and/or hypothermia), measurement of serum thyroid-stimulating hormone and free thyroxine is indicated, regardless of NBS results.

A retrospective study on newborn screening for metabolic disorders

The process of testing newborn infants for hormonal, genetic, metabolic, and other disorders is known as newborn screening (NSB). Newborn screening is essential for detecting, diagnosing, and treating disorders that could save serious consequences for a newborn's health. Congenital Hypothyroidism (CH), Cystic Fibrosis (CF), Glucose-6-phosphate dehydrogenase (G6PD) deficiency, and Profound Biotinidase deficiency (BD) are common disorders in India. A retrospective analysis of the results of NBS by Cord blood spots was performed at the department of Obstetrics and Gynecology, 7 Airforce Hospital, Kanpur, Uttar Pradesh, from June 2022 to September 2022. During this period, 26 newborns were screened for four disorders, including CH, CF, G6PD deficiency, and BD. In this investigation, no cases of CH, CF, G6PD deficiency, or BD were found to be positive. The results of the current data provide a distinct opportunity to investigate the birth prevalence of inborn metabolic disorders in the area close to the city of Kanpur.

Genetic Factors Causing Thyroid Dyshormonogenesis as the Major Etiologies for Primary Congenital Hypothyroidism: Clinical and Genetic Characterization of 33 Patients

BACKGROUND AND AIMS

Although the significance of primary congenital hypothyroidism (CH) is supported by an increasing amount of evidence, the clinical and genetic characteristics of this condition are still poorly understood. This study aimed to explore the underlying genetic etiologies in a cohort of primary CH patients.

SUBJECTS AND METHODS

The clinical data of 33 patients with primary CH were collected and analyzed via a cross-sectional study. Genetic analysis was performed by high-throughput sequencing and Sanger verification, and the pathogenicity of the novel missense variants was predicted using a variety of comprehensive bioinformatic tools.

RESULTS

Among the 33 patients, 22 (22/33, 66.7%) harbored pathogenic variants in the causative genes of thyroid dysgenesis or dyshormonogenesis, with DUOX2 (15/33, 45.5%) topping the list, followed by TG, TPO, DUOXA2 and PAX8. Four novel genetic variants were detected, including a pathogenic frameshift and three likely pathogenic missense variants. Positive neonatal screening for TSH, neonatal jaundice and abnormal thyroid morphology were the main positive findings among all cases. Although 31 of the total 33 CH patients exhibited normal anthropometric and social performance, the other 2 had poor prognosis in this study.

CONCLUSIONS

This study reported 33 new CH patients bearing four novel genetic variants, which enriched the variant spectrum of CH genes. In this cohort, genetic factors causing thyroid dyshormonogenesis were the main etiologies of CH development. Most patients exhibited a favorable prognosis; however, systematic management remains a challenge in achieving improved clinical outcomes for CH patients.

Guidelines for Newborn Screening of Congenital Hypothyroidism (2021 Revision)

Purpose of developing the guidelines: Newborn screening (NBS) for congenital hypothyroidism (CH) was started in 1979 in Japan, and early diagnosis and treatment improved the intelligence prognosis of CH patients. The incidence of CH was once about one in 5,000-8,000 births, but has been increased with diagnosis of subclinical CH. The disease requires continuous treatment and specialized medical facilities should conduct differential diagnosis and treatment in patients who are positive by NBS to avoid unnecessary treatment. The Guidelines for Mass Screening of Congenital Hypothyroidism (1998 version) were developed by the Mass Screening Committee of the Japanese Society for Pediatric Endocrinology in 1998. Subsequently, the guidelines were revised in 2014. Here, we have added minor revisions to the 2014 version to include the most recent findings. Target disease/conditions: Primary congenital hypothyroidism. Users of the Guidelines: Physician specialists in pediatric endocrinology, pediatric specialists, physicians referring pediatric practitioners, general physicians, laboratory technicians in charge of mass screening, and patients.

Etiological, clinical, and laboratory evaluation of congenital hypothyroidism and determination of levothyroxine (LT4) dose at treatment interruption in differentiating permanent vs. transient patients

BACKGROUND

Congenital hypothyroidism (CH) is the most common cause of preventable but irreversible mental retardation in children, although the risk has been widely abolished by national neonatal screening programs. The aim of this study was to determine, (a) the cause of CH, (b) the etiological cause of persistent CH and (c) to investigate the role of laboratory and clinical data in predicting persistent and transient CH.

METHODS

Patients diagnosed with CH, who started L-thyroxine treatment and were followed up for at least three years were included. Patient data were reviewed retrospectively. Serum thyroid hormones were measured four weeks after discontinuation of therapy at age three or earlier. Cases with a thyroid-stimulating hormone (TSH) value of >10 mIU/mL were accepted as permanent hypothyroidism, while cases with normal TSH values for six months after cessation were accepted as transient hypothyroidism.

RESULTS

There were 232 treated cases, of whom 108 (46.6%) were female, and 169 (72.8%) were eventually diagnosed with transient CH. The best cut-off point for predicting permanent status was determined as LT4 cut-off dose ≥1.45 mcg/kg/day. The median (range) duration of L-thyroxine treatment in transient hypothyroid cases was 24 (range: 6-36) months, and treatment was discontinued before the age of three years in 64%.

DISCUSSION

There were 232 treated cases, of whom 108 (46.6%) were female, and 169 (72.8%) were eventually diagnosed with transient CH. The best cut-off point for predicting permanent status was determined as LT4 cut-off dose ≥1.45 mcg/kg/day. The median (range) duration of L-thyroxine treatment in transient hypothyroid cases was 24 (range: 6-36) months, and treatment was discontinued before the age of three years in 64%.

Evaluation of permanent and transient congenital hypothyroidism in cases referred from National Neonatal Screening Program

AIM

The incidence of congenital hypothyroidism (CH) has increased world-wide. Lowering cut-off in screening programs has led to an increase in the rate of transient CH. We aimed to evaluate the rates of permanent and transient CH in cases referred from the screening program and to investigate the clinical and laboratory factors which predict transient CH.

METHODS

In 109 cases referred from the neonatal screening program to our hospital, from September 2015 to April 2018, 52 primarily diagnosed CH cases were prospectively evaluated. Regularly followed up, 44 CH cases were included in the study at the end of 3 years.

RESULTS

38.2 ± 1.31 weeks (w) and mean birthweight 3021.3 ± 389.6 gram (g) in the transient CH group; both were significantly lower compared to permanent CH cases with 39.06 ± 1.33 w and 3375.3 ± 425.3 g (P = 0.025, P = 0.007) respectively. Transient CH rate was found to be 50% (all hypoplastic) in the dysgenesis group and 73.3% in groups with normal and hyperplasic thyroid gland. While fT₄ , thyroid-stimulating hormone, and thyroglobulin levels at diagnosis do not predict transient/permanent CH, levothyroxine (LT-4) dosage was significantly lower in the transient CH group in all years. The optimal cut-off value with highest sensitivity and specificity for LT-4 dosage as a predictive marker to differentiate transient CH from permanent CH was 2.27 μg/kg/day (P = 0.004; sensitivity: 71%, specificity: 83%) at 1st year, 1.85 μg /kg/day (P = 0.013; sensitivity: 66%, specificity: 72%) at 2nd year and 1.69 μg /kg/day at 3rd year (P < 0.0001; sensitivity: 90%, specificity: 83%).

CONCLUSION

Transient CH is more frequent than expected. Our results suggest that LT-4 requirement may be a good marker for predicting transient CH, while thyroid hormone levels at the time of diagnosis do not significantly predict permanent and transient CH. Therefore, infants with CH requiring LT-4 doses <2.27 μg/kg/day at 1st year, <1.85 μg /kg/day at 2nd year may be re-evaluated earlier to discriminate transient CH rather than at 3 years of age.

[Thyrotoxicosis in a patient with Turner syndrome: radioactive iodine therapy]

Turner syndrome (TS) is a chromosomal disorder affecting female and characterized by complete or partial monosomy of the X chromosome. These genetic changes lead to the abnormalities in growth and development and increase the risk of autoimmune diseases, including those affecting the thyroid. Thyroid pathology in TS may include autoimmune thyroiditis, hypothyroidism, thyrotoxicosis (Graves disease, AIT in the hyperthyroid state).Thyrotoxicosis is the clinical syndrome of excess circulating thyroid hormones. One of the main causes of thyrotoxicosis is Graves' disease (GD), an organ-specific autoimmune disease caused by the production of stimulating thyrotropin receptor antibodies. There are three treatment options for thyrotoxicosis: anti-thyroid drugs, radioactive iodine and thyroidectomy. A personalized approach to disease management is especially important in cases of genetic diseases.We present a clinical case of a patient with TS and GD, who has been referred to a radiologist at the Department of Radionuclide Therapy of Endocrinology Research Center. The patient was diagnosed with congenital hypothyroidism at neonatal screening, but thyroid hormones therapy was initiated aged three. Based on the survey, GD was diagnosed aged twenty one. Anti-thyroid drug therapy was started, which resulted in toxic hepatitis. Taking into account intolerance to anti-thyroid drugs, radioiodine therapy has been recommended, which led to hypothyroidism.