Incidence of congenital hypothyroidism in China: data from the national newborn screening program, 2013-2015

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.

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.

An Insight into Indonesia's Challenges in Implementing Newborn Screening Programs and Their Future Implications

Due to high entry barriers, countries might find it daunting to implement the NBS program, especially those just trying to start it. This review aims to discuss Indonesia's barriers that hinder newborn screening (NBS) implementation while discussing the future implications. Literature in Pubmed and Google Scholar was scoured with keywords such as "Newborn Screening", "Neonatal Screening", "Indonesia", "Asia Pacific", "Barriers", and "Challenges". We also searched for relevant references in those published articles. Grey literature, such as state regulations, informative webinars on the topics by experts regarding current situations, and press releases by the Indonesian Minister of Health (MoH), was also searched. Newborn screening is no longer considered just a laboratory test but an array of well-harmonized systems that must be orchestrated well. Some of the barriers Indonesia faces in implementing NBS are a lack of prevalence data, ethical issues, infrastructure, cost-benefit analysis, logistical issues, government support, patient issues, a lack of commitments, and a lack of healthcare workers, specialization, and training. Government support with professional advocates and support groups, proper infrastructure, and a single-payer system for NBS programs are necessary to accelerate NBS programs in Indonesia.

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.

Effects of a false-positive result in newborn congenital hypothyroidism screening on parents in Guangxi, China

Background

As more than 500,000 neonates participate in newborn congenital hypothyroidism (CH) screening in Guangxi Zhuang Autonomous Region each year, the overall number of false-positive (FP) cases has increased. We aim to assess the parental stress in parents of neonates with FP CH results in Guangxi, find out the influence factors related to demographics, and provide the basis for personalized health education.

Methods

The parents of neonates with FP CH results were invited to participate in the FP group, and the parents of neonates with all negative results were invited to participate in the control group. The parents completed a questionnaire on demographics, knowledge of CH, and the parental stress index (PSI) in the hospital for the first time. The follow-up visits for PSI were conducted 3, 6, and 12 months afterward through telephone and online.

Results

A total of 258 and 1,040 parents participated in the FP and control groups, respectively. The parents in the FP group had better knowledge of CH and higher PSI scores than the parents in the control group. The result of logistic regression showed that the major influence factors related to the knowledge of CH were FP experience and source of knowledge. The parents in the FP group who were well-informed during the recall phone call had lower PSI scores than the other parents. The parents in the FP group showed decreasing PSI scores gradually in follow-up visits.

Conclusion

The results suggested that FP screening results may affect parental stress and parent-child relationship. FP results increased the stress on the parents and increased their knowledge of CH passively.

Developmental Trends in Postnatal Thyroid Hormones and Thyroid Dysfunction in Preterm Infants Born at less than 34 weeks Gestation

OBJECTIVES

To analyse the trends in thyroid function tests (TFT) in preterm infants, evaluate the frequency of thyroid dysfunction, and identify the factors that influence thyroid function.

METHODS

The TFT results and risk factors for thyroid dysfunction in preterm infants with gestational ages (GA) between 25 and 34 weeks were analysed.

RESULTS

In total, 535 infants were enrolled in this study. Thyroid hormone levels vary with gestational and postnatal age, and the total frequency of thyroid dysfunction is 50.3%. Thirty-one infants (5.8%) had delayed TSH elevation. Transient hypothyroxinaemia of prematurity remained significantly associated with both lower birth weight and GA. Congenital hypothyroidism was significantly associated with lower birth weight, 5 min Apgar score, and dopamine use.

CONCLUSIONS

Thyroid hormone levels in preterm infants are related to gestation and postnatal age, the frequency of thyroid dysfunction in premature infants is high, and is negatively correlated with GA and birth weight.

Clinical Utility of Medical Exome Sequencing: Expanded Carrier Screening for Patients Seeking Assisted Reproductive Technology in China

Purpose: Expanded carrier screening (ECS) is an effective method to identify at-risk couples (ARCs) and avoid birth defects. This study aimed to reveal the carrier spectrum in the Chinese population and to delineate an expanded carrier gene panel suitable in China.

Methods: Medical exome sequencing (MES), including 4,158 disease-causing genes, was offered to couples at two reproductive centers. It was initially used as a diagnostic yield for potential patients and then used for ECS. Clinical information and ECS results were retrospectively collected.

Results: A total of 2,234 couples, representing 4,468 individuals, underwent MES. In total, 254 individuals showed genetic disease symptoms, and 56 of them were diagnosed with genetic diseases by MES. Overall, 94.5% of them were carriers of at least one disease-causing variant. The most prevalent genes were GJB2 for autosomal recessive disorders and G6PD for X-linked diseases. The ARC rate was 9.80%, and couples were inclined to undergo preimplantation genetic testing when diseases were classified as “profound” or “severe.”

Conclusion: This study provided insight to establish a suitable ECS gene panel for the Chinese population. Disease severity significantly influenced reproductive decision-making. The results highlighted the importance of conducting ECS for couples before undergoing assisted reproductive technology.

Insights of Noncanonical Splice-site Variants on RNA Splicing in Patients With Congenital Hypothyroidism

CONTEXT

Congenital hypothyroidism (CH) is caused by mutations in the genes for thyroid hormone synthesis. In our previous investigation of CH patients, approximately 53% of patients had mutations in either coding exons or canonical splice sites of causative genes. Noncanonical splice-site variants in the intron were detected but their pathogenic significance was not known.

OBJECTIVE

This work aims to evaluate noncanonical splice-site variants on pre-messenger RNA (pre-mRNA) splicing of CH-causing genes.

METHODS

Next-generation sequencing data of 55 CH cases in 47 families were analyzed to identify rare intron variants. The effects of variants on pre-mRNA splicing were investigated by minigene RNA-splicing assay.

RESULTS

Four intron variants were found in 3 patients: solute carrier family 26 member 4 (SLC26A4) c.1544+9C>T and c.1707+94C>T in one patient, and solute carrier family 5 member 5 (SLC5A5) c.970-48G>C and c.1652-97A>C in 2 other patients. The c.1707+94C>T and c.970-48G>C caused exons 15 and 16 skipping, and exon 8 skipping, respectively. The remaining variants had no effect on RNA splicing. Furthermore, we analyzed 28 previously reported noncanonical splice-site variants (4 in TG and 24 in SLC26A4). Among them, 15 variants (~ 54%) resulted in aberrant splicing and 13 variants had no effect on RNA splicing. These data were compared with 3 variant-prediction programs (FATHMM-XF, FATHMM-MKL, and CADD). Among 32 variants, FATHMM-XF, FATHMM-MKL, and CADD correctly predicted 20 (63%), 17 (53%), and 26 (81%) variants, respectively.

CONCLUSION

Two novel deep intron mutations have been identified in SLC26A4 and SLC5A5, bringing the total number of solved families with disease-causing mutations to approximately 45% in our cohort. Approximately 46% (13/28) of reported noncanonical splice-site mutations do not disrupt pre-mRNA splicing. CADD provides highest prediction accuracy of noncanonical splice-site variants.

Diagnostic re-evaluation and predictors of congenital hypothyroidism with eutopic thyroid gland in Jiangxi, China

OBJECTIVES

An increase in the incidence of congenital hypothyroidism (CH) with eutopic gland has been reported worldwide due to neonatal screening programs. In this study, we aimed to determine the prevalence of transient CH (TCH) and to investigate predictive factors that could distinguish between permanent and transient CH in patients with eutopic thyroid glands.

METHODS

We retrospectively reviewed 508 children treated for CH with eutopic thyroid glands between June 1998 and June 2020 in Jiangxi Newborn Screening Center. All patients were treated with levothyroxine and underwent Diagnostic re-evaluation after 2-3 years of age. Patients were classified as having TCH or permanent CH (PCH) during follow-up.

RESULTS

Of the 508 patients initially treated for CH with a normally located gland, 335 patients (65.9%) were classified in the TCH group and 173 (34.1%) in the PCH group based on the defined criteria. Multivariate analysis revealed that TCH was associated with a lower levothyroxine dose at 24 months of age (p<0.001) and a lower likelihood of having a first-degree family history of CH (p=0.026) than PCH. Gender, prematurity, low birth weight, initial CH severity such as serum TSH and FT4 levels, or bone maturation delay at diagnosis had no effect. Receiver operating characteristics curve analysis showed that a cutoff of 2.3 μg/kg/day for levothyroxine dose requirement at 24 months of age had a sensitivity of 71% and a specificity of 70% for predicting transient CH, with values below this threshold considered predictive of transient CH.

CONCLUSIONS

TCH presents a significant portion of patients with CH. The levothyroxine dose requirement at 24 months of age has a predictive role in differentiating TCH from PCH in CH patients with eutopic thyroid glands.

Birth prevalence of tetrahydrobiopterin deficiency in China: data from the national newborn screening program, 2013-2019

BACKGROUND

Tetrahydrobiopterin deficiency (BH4D), a less common form of hyperphenylalaninemia (HPA), can lead to severe developmental retardation if untreated. Little has been reported on the prevalence of BH4D among live births worldwide. This study examined its prevalence across China and between geographical areas within the country.

METHODS

We analyzed data from the Chinese national screening program for HPA in newborns between 2013 and 2019. BH4D prevalence was examined by province, region and the entire country. Provincial-level prevalence was estimated from the number of confirmed BH4D cases and screened newborns, after adjusting for HPA-positive recall rate. Regional- and national-level prevalences were estimated by summing provincial-level prevalences after weighting them by the number of live births. A Poisson distribution was assumed in order to calculate 95% confidence intervals (CIs) for prevalence.

RESULTS

Among 107,078,115 newborns screened for HPA in China, 380 with BH4D were identified, corresponding to a total prevalence of 3.8 per 1,000,000 live births. Prevalence was higher in eastern regions (5.9 per 1,000,000) and northern regions (4.1 per 1,000,000) of China than in southern regions (1.6 per 1,000,000) or northwestern regions (1.7 per 1,000,000). Across the entire country, 3.9% cases of HPA were diagnosed as BH4D, and this proportion reached as high as 15.1% in the southern part of the country.

CONCLUSIONS

These first insights into BH4D prevalence across China suggest slightly higher prevalence than in other countries, and it varies substantially by region. More attention should be paid to early diagnosis and timely treatment of BH4D.

Geographic variations in the incidence of congenital hypothyroidism in China: a retrospective study based on 92 million newborns screened in 2013-2018

Background:

Although congenital hypothyroidism (CH) has been widely studied in Western countries, CH incidence at different administrative levels in China during the past decade remains unknown. This study aimed to update the incidence and revealed the spatial pattern of CH incidence in the mainland of China, which could be helpful in the planning and implementation of preventative measures.

Methods:

The data used in our study were derived from 245 newborns screening centers that cover 30 provinces of the Chinese Newborn Screening Information System. Spatial auto-correlation was analyzed by Global Moran I and Getis-Ord Gi statistics at the provincial level. Kriging interpolation methods were applied to estimate a further detailed spatial distribution of CH incidence at city level throughout the mainland of China, and Kulldorff space scanning statistical methods were used to identify the spatial clusters of CH cases at the city level.

Results:

A total of 91,921,334 neonates were screened from 2013 to 2018 and 42,861 cases of primary CH were identified, yielding an incidence of 4.66 per 10,000 newborns screened (95% confidence interval [CI]: 4.62–4.71). Neonates in central (risk ratio [RR] = 0.84, 95% CI: 0.82–0.85) and western districts (RR = 0.71, 95% CI: 0.69–0.73) had lower probability of CH cases compared with the eastern region. The CH incidence indicated a moderate positive global spatial autocorrelation (Global Moran I value = 0.394, P < 0.05), and the CH cases were significantly clustered in spatial distribution. A most likely city-cluster (log-likelihood ratio [LLR] = 588.82, RR = 2.36, P < 0.01) and 25 secondary city-clusters of high incidence were scanned. The incidence of each province and each city in the mainland of China was estimated by kriging interpolation, revealing the most affected province and city to be Zhejiang Province and Hangzhou city, respectively.

Conclusion:

This study offers an insight into the space clustering of CH incidence at provincial and city scales. Future work on environmental factors need to focus on the effects of CH occurrence.

Maternal exposure to O3 and NO2 may increase the risk of newborn congenital hypothyroidism: a national data-based analysis in China

Maternal exposure to air pollution during pregnancy is associated with adverse outcomes in the offspring, but limited studies focused on the impacts of gaseous air pollution on newborn congenital hypothyroidism (CH). Therefore, a national data-based analysis was conducted to explore the association between maternal exposure to gaseous air pollution and the incidence of CH in China. Annual average exposure levels of SO₂, NO₂, CO, and O₃ from January 1, 2014, to December 30, 2014, were acquired from the Chinese Air Quality Online Monitoring and Analysis Platform. The annual incidence of newborn CH from October 1, 2014, to September 30, 2015, was collected from the Chinese Maternal and Child Health Surveillance Network. Temperature and toxic metal in wastewater in 2014 were also collected as covariates. Maternal exposure to O₃ and NO₂ in 1 μg/m³ level increment was positively associated with newborn CH, with an OR of 1.055 (95% CI 1.011, 1.102) and 1.097 (95% CI 1.019, 1.182) after adjusting for covariates completely. Compared with the lowest level of O₃, maternal exposure to the 4th quartile of O₃ was positively associated with newborn CH (OR 1.393, 95% CI 1.081, 1.794) after adjusting for covariates completely. And the 3rd and 4th quartiles of NO₂ were associated positively with CH (OR 1.576, 95% CI 1.025, 2.424, and OR 1.553, 95% CI 0.999, 2.414, respectively) compared with the lowest level of NO₂. By fitting the ROC curve, 93.688 μg/m³ in O₃ might be used as cutoff to predict the incidence of newborn CH in China.

First Experiences with Newborn Screening for Congenital Hypothyroidism in Ulaanbaatar, Mongolia

Congenital hypothyroidism (CH) is among the most common conditions leading to intellectual disability, which can be prevented by early detection through newborn screening (NBS). In Mongolia, a regional screening program for CH was launched in 2000, which was supported by the International Atomic Energy Agency (IAEA) for the Asia Pacific Region. In our present study, a total of 23,002 newborns from nine districts in Ulaanbaatar were screened between 2012 and 2020, by the measurement of the thyroid-stimulating hormone (TSH) from dried blood spots, sampled 24 to 72 h after birth. The level of TSH was measured by the DELFIA assay. The overall CH prevalence confirmed at birth was 1/2091. The female-to-male ratio for CH cases was 1.8:1. The majority of patients were asymptomatic (72.7% of CH cases); umbilical hernia and cold or mottled skin were reported symptoms in patients with CH (27.3%). Thyroid dysgenesis (hypoplasia and agenesis) was the most common etiology, with a total of nine cases (81.8%) out of the eleven patients. The lapse between the birth date and the initiation of L-thyroxine treatment in CH-positive children was lower than 15 days in 63.64% of cases or 15 to 30 days in 36.36% of children. Further research is required to expand the screening coverage for CH in Mongolia.

Risk factors for transient and permanent congenital hypothyroidism: a population-based case-control study

Background

Congenital hypothyroidism (CH) is the most important cause of mental and physical retardation in newborns. The prevalence of CH has been reported high in East Azerbaijan province of Iran. However, the risk factors for CH are poorly understood. This study aimed to determine and compare risk factors for permanent and transient CH in East Azerbaijan, Iran.

Methods

A case-control study was conducted in the Iranian national screening program for CH. This study included 680 neonates: 340 neonates with confirmed CH and 340 matched healthy controls born at the same period and from the same residential area as the cases. Multiple logistic regression analyses were used to estimate the crude and adjusted odds ratios and 95% confidence intervals for the association between different risk factors and transient and permanent CH.

Results

Out of the 680 participants, 364 (53.53%) were male. Family history of CH (OR = 5.09, 95% CI: 1.66–15.63), neonatal jaundice (OR = 3.89, 95% CI: 2.36–6.43) and parental consanguineous relation (OR = 2.19, 95% CI: 1.51–3.17) were associated with an increased risk of permanent CH. Likewise, the use of Betadine in pregnancy (OR = 4.87, 95% CI: 1.45–16.28), family history of CH (OR = 5.98, 95% CI: 2.04–17.48), neonatal jaundice (OR = 2.81, 95% CI: 1.75–4.52), parental consanguineous relation (OR = 3.86, 95% CI: 1.92–5.74), and gestational age at birth (OR = 3.2, 95% CI: 1.90–5.41) were identified as risk factors for transient CH.

Conclusion

Family history, neonatal jaundice, gestational age at birth, and Betadine usage in pregnancy are associated with CH.

[Risk factors for neonatal congenital hypothyroidism: a Meta analysis]

OBJECTIVE

To investigate the risk factors for congenital hypothyroidism (CH) in neonates, and to provide a reference for the prevention of CH.

METHODS

The databases including China Biomedical Literature Service System, China National Knowledge Infrastructure, Wanfang Data, and Weipu Periodical Database, PubMed, Web of Science, Embase, SpringerLink, and Elsevier/ScienceDirect were searched for studies on the risk factors for CH in neonates published up to August 1, 2020. R 3.6.2 and RevMan 5.3 software were used to perform a Meta analysis.

RESULTS

A total of 20 studies were included, with 13 case-control studies and 7 cross-sectional studies. There were 11 564 neonates in total, with 3 579 neonates in the case group and 7 985 neonates in the control group. The Meta analysis showed that advanced maternal age (OR=2.111, 95%CI: 1.275-3.493), thyroid disease during pregnancy (OR=3.365, 95%CI: 1.743-6.500), gestational diabetes mellitus (OR=2.158, 95%CI: 1.545-3.015), anxiety (OR=3.375, 95%CI: 2.133-5.340), medication during pregnancy (OR=2.774, 95%CI: 1.344-5.725), radiation exposure during pregnancy (OR=3.262, 95%CI: 1.950-5.455), family history of thyroid disease (OR=8.706, 95%CI: 5.991-12.653), low birth weight (OR=2.674, 95%CI: 1.895-3.772), fetal macrosomia (OR=1.657, 95%CI: 1.187-2.315), preterm birth (OR=2.567, 95%CI: 2.070-3.183), post-term birth (OR=2.083, 95%CI: 1.404-3.091), twin pregnancy or multiple birth (OR=3.455, 95%CI: 1.958-6.096), and birth defects (OR=6.038, 95%CI: 3.827-9.525) were risk factors for CH in neonates.

CONCLUSIONS

Advanced maternal age, gestational thyroid disease, gestational diabetes mellitus, anxiety, medication during pregnancy, radiation exposure during pregnancy, family history of thyroid disease, low birth weight, fetal macrosomia, preterm birth, post-term birth, twin pregnancy or multiple pregnancy, and birth defects may increase the risk of CH in neonates.

Screening and Functional Analysis of TPO Gene Mutations in a Cohort of Chinese Patients With Congenital Hypothyroidism

BACKGROUNDS

As a crucial enzyme in thyroid hormone synthesis, the genetic defective thyroid peroxidase (TPO) was one of the main genetic factors leading to congenital hypothyroidism (CH).

METHODS

Mutations in the TPO gene were screened and identified in 219 patients with CH from northwest China by using high-throughput sequencing and bioinformatics analysis. The biological function of detected variants was studied by in vitro experiments and homology modeling.

RESULTS

Nineteen rare variants, including seven novel ones, were detected in 17 of 219 patients (7.8%). Most cases were detected with one single heterozygous variant, and only two patients were detected with multiple variants, i.e., compounds for (1) IVS7-1G>A, p.Ala443Val, and p.Arg769Trp and (2) p.Asn592Ser and p.Asn798Lys. The biological function of the four missense mutations (i.e., p.Ala443Val, p.Arg769Trp, p.Asn592Ser, and p.Asn798Lys) they carried were further studied. Experimental data showed that these four mutations did not affect the protein expression level of the TPO gene but remarkably reduced the peroxidase activity toward guaiacol oxidation, retaining 8-32% of activity of the wild-type protein. The comparison of the predicted 3-D structures of wild-type and mutant TPO proteins showed that these four amino acid substitutions changed the non-covalent interactions of studied residues that might alter the structure and function of the TPO protein.

CONCLUSION

This study was the first to analyze the TPO mutation spectrum of patients with CH in northwest China. Our data indicated that the TPO mutation was not a common reason to cause CH in China. The functional data may help to clarify the structure-function relationship of the TPO protein and provide further evidence for the elucidation of the genetic etiology of CH.

Analysis of Mutation Spectra of 28 Pathogenic Genes Associated With Congenital Hypothyroidism in the Chinese Han Population

PURPOSE

Congenital hypothyroidism (CH) is the most common neonatal endocrine disease; its early detection ensures successful treatment and prevents complications. However, its molecular etiology remains unclear.

METHODS

We used second-generation sequencing to detect 28 pathogenic genes in 15 Chinese Han patients with CH in Shenzhen, China, and analyzed the genetic pattern of the pathogenic genes through their pedigrees. The pathogenicity assessment of gene mutations was performed based on the American College of Medical Genetics and Genomics (ACMG) classification guidelines, inheritance models, and published evidence.

RESULTS

Mutations in several target genes were identified in 14 of 15 patients (93.33%); these mutations were distributed in eight genes (DUOX2, DUOXA2, TPO, TG, TSHR, FOXE1, KDM6A, and POU1F1). DUOX2 exhibited the highest mutation frequency (44%, 11/25), followed by TPO (16%, 4/25) and TG (16%, 4/25). DUOX2 exhibited the highest biallelic mutation (7/15). Eight out of 25 variants verified by the ACMG guidelines were classified as pathogenic (P, category 1) or possibly pathogenic (LP, Type 2), namely six variants of DUOX2, and one variant of TPO and DUOXA2. Five new mutations were detected: one in DUOX2, which was located in the splicing region of mRNA (c.1575-1G>A), three new missense mutants, p.A291T, p.R169W, and p. S1237dup, and one new TPO missense variant c.2012G>T (p.W671L). The main criteria for determining the genotype-phenotype relationship were a diagnostic detection rate of 53.33% (8/15) and combination of three or more gene mutations.

CONCLUSIONS

CH gene mutations in the population may be mainly manifested in genes influencing thyroid hormone synthesis, such as DUOX2 compound heterozygous mutations, which exhibited a high detection rate. The clinical manifestations are diverse, and mainly include transient CH. Therefore, genetic screening is recommended for CH patients to determine the correlation between clinical phenotypes and gene mutations, which will assist in clinical management.

Assessment of intelligence quotient score in children at the age of six with suspected congenital hypothyroidism: A retrospective cohort study

Background: The clinical suspicion of Congenital Hypothyroidism (CH) is identified by abnormal results in the first test of Thyroid Stimulating Hormone (TSH) (5-9.9 mIU/L), and normal results in re-test (TSH<4 mIU/L). The CH has a contribution to physical and mental health. This study aimed to determine the Intelligence Quotient (IQ) score in children with suspected congenital hypothyroidism.

Methods: This research is a retrospective cohort study conducted in Mashhad, Iran. The IQ scores of 1976 children at the age of 6 were considered as an outcome variable. The history of CH screening for each newborn was assessed, then all suspected CH newborns that diagnosed healthy in re-test were considered as an exposed group, the effects of this situation on IQ score was assessed using logistic regression. All analysis was performed in STATA.

Results: The averages of IQ score (p<0.001), weight (p=0.024), and height (p<0.001) in the exposed group were lower than the unexposed group. The exposed group was related to those whose parental education was less or equal to 12 years (p<0.001). Similarly, the history of CH and maternal education for ≤12 years were detected as risk factors for having an IQ score of <90 in children.

Conclusion: Aside from the link between parental education and clinical suspicion of CH in neonates, our findings underline the possible strong effect of CH status and maternal education for ≤12 years on reducing IQ scores in the next years of child life.

Congenital Hypothyroidism and its Related Factors in an Iranian Population: A Retrospective Study in Semnan (2011-2016)

Background:

Congenital hypothyroidism (CH) is an important and preventable cause of intellectual disability. This study determined the incidence of CH and its related factors in Semnan city in Iran.

Methods:

All neonates born in Semnan from 2011 to 2016 who participated in a screening program for CH were evaluated to estimate the incidence of CH. In a nested case-control study, all diagnosed CH cases were compared with a control group of healthy newborns. Statistical analysis used conditional logistic regression model with STATA-14.

Results:

106 out of 17,507 neonates born in Semnan during 2011–2016 were diagnosed with CH (6.05 cases per 1,000 live births). Maternal parity (odds ratio [OR] =1.78, P = 0.044), birth weight (OR = 0.29, P = 0.001), parental history of thyroid disease (OR = 3.43, P = 0.001), father's education (OR = 0.71, P = 0.003), father's occupation (nonworker) (OR = 2.97, P = 0.001), and the presence of other anomalies (OR = 4.14, P = 0.037) were related to the incidence of CH.

Conclusions:

The cumulative incidence of CH in Semnan was higher than in both the global and national statistics. Aside from well-known medical determinants, some important social factors such as father's occupation and education have a significant and independent relationship with occurrence of CH; rational attention should be given to them in health care programs to increase the effectiveness of preventative measures for CH.

DUOX2 variants are a frequent cause of congenital primary hypothyroidism in Thai patients

OBJECTIVE

To identify the genetic etiologies of congenital primary hypothyroidism (CH) in Thai patients.

DESIGN AND METHODS

CH patients were enrolled. Clinical characteristics including age, signs and symptoms of CH, pedigree, family history, screened thyroid-stimulating hormone results, thyroid function tests, thyroid imaging, clinical course and treatment of CH were collected. Clinical exome sequencing by next-generation sequencing was performed. In-house gene list which covered 62 potential candidate genes related to CH and thyroid disorders was developed for targeted sequencing. Sanger sequencing was performed to validate the candidate variants. Thyroid function tests were determined in the heterozygous parents who carried the same DUOX2 or DUOXA2 variants as their offsprings.

RESULTS

There were 118 patients (63 males) included. Mean (SD) age at enrollment was 12.4 (7.9) years. Forty-five of 118 patients (38%) had disease-causing variants. Of 45 variants, 7 genes were involved (DUOX2, DUOXA2, TG, TPO, SLC5A5, PAX8 and TSHR). DUOX2, a gene causing thyroid dyshormonogenesis, was the most common defective gene (25/45, 56%). The most common DUOX2 variant found in this study was c.1588A>T. TG and TPO variants were less common. Fourteen novel variants were found. Thyroid function tests of most parents with heterozygous state of DUOX2 and DUOXA2 variants were normal.

CONCLUSIONS

DUOX2 variants were most common among Thai CH patients, while TG and TPO variants were less common. The c.1588A>T in DUOX2 gene was highly frequent in this population.

Ethnic preference distribution of inborn errors of metabolism: A 4-year study in a multi-ethnic region of China

Chinese newborns have been screened for inborn errors of metabolism (IEM) for over 20 years. Although China features 56 different ethnic groups, there are no specific data describing the incidence of such genetic errors across difference ethnicities. To understand the ethnic preference distribution of the incidence and variants of IEM in the Ningxia Hui Autonomous Region of China, 189,354 newborns from 2016 to 2019 were screened by tandem mass spectrometry, including 87,482 from the Han ethnic population, 88,229 from the Hui population, 1,103 from other ethnicities, and 12,540 infants without ethnic registration. Suspected cases then underwent specific genetic profiling by targeted next generation sequencing. In total, 160 patients were diagnosed with 17 types of IEM, with a significant higher incidence in Hui infants (1/1,003) than in Han infants (1/1,232). Five diseases (eight patients) were specifically detected in Han infants, while three were exclusively diagnosed in six Hui infants. For shared diseases, the variants of keys genes also showed ethnic preference. Our findings enhance our understanding of the genetics underlying IEM, thus promoting the development of treatment plans for patients from different areas or ethnicities in China.

Perinatal risk factors for congenital hypothyroidism: A retrospective cohort study performed at a tertiary hospital in China

Congenital hypothyroidism (CH) is one of the most common neonatal endocrine diseases. This retrospective cohort study aimed to identify the potential perinatal risk factors for CH and to differentiate between transient and permanent CH (TCH and PCH, respectively) as well as determine their prevalence in a southeastern Chinese population.This study was based on an 18-year surveillance of a neonatal CH screening program in a large tertiary hospital. A retrospective review of the maternal and neonatal perinatal exposures was conducted.Of the 205,834 newborns screened between 2000 and 2018, 189 were diagnosed with CH (1/1089). Among the 131 CH patients who again underwent thyroid function testing (TFT) after discontinuation of levothyroxine at the age of 3 years, 61 (46.6%) were diagnosed with PCH and 70 (53.4%) were diagnosed with TCH. In the maternal characteristics model, women aged 35 years or older and those who had thyroid disease and/or diabetes mellitus during pregnancy had increased risk of having an offspring with CH (P = .001, .000, and .001, respectively). Significant associations were found with regard to parity and the risk of CH in the offspring (P = .000). In the neonatal characteristics model, infants with female sex, preterm birth, post-term birth, low birth weight, other birth defects, and those born as part of multiple births (P = .011, .034, .001, .000, .000, and .003, respectively) had increased risk of CH. The rate of newborns with other birth defects was higher in the PCH group than that in the TCH group (P = .008), whereas the rate of maternal thyroid disease, newborns with low birth weight, and newborns with preterm birth was higher in the TCH group than that in the PCH group (P = .041, .020, and .013, respectively). The levothyroxine dose (μg/kg/day) at 1 year, 2 years, and 3 years old was significantly lower in the TCH group than that in the PCH group (P = .000, .000, and .000, respectively).Perinatal factors should be considered during the diagnosis and treatment of CH.

Mutation spectrum analysis of 29 causative genes in 43 Chinese patients with congenital hypothyroidism

Congenital hypothyroidism (CH) is the most common neonatal endocrine disorder with a genetic origin. The purpose of the present study was to analyze the mutation spectrum of CH patients in China. A targeted next-generation sequencing panel covering all exons of 29 CH-related causative genes was used in 43 Han Chinese patients with CH [11 dysgenesis and 32 glands in situ (GIS)]. The functional impact and pathogenicity of detected variants were analyzed using a comprehensive bioinformatics approach and co-segregation studies. A total of 47 rare non-polymorphic variants in 9 target genes associated with thyroid hormone synthesis (DUOX2, DUOXA2, TPO, TG, SLC26A4 and SLC5A5), thyroid stimulating hormone resistance (TSHR) and central hypothyroidism (PROP1 and TRHR) were identified in 31 patients (31/43, 72%). Of these variants, 8 were novel, including 3 in DUOX2, 2 in TPO, 3 in TSHR and 1 in SLC5A5. Variants were mostly affected by DUOX2, TG, TPO and TSHR. Approximately 44% of the patients (19/43) carried DUOX2 variants. The mutation detection rates in patients with GIS were higher compared with patients with dysgenesis [25/32 (78%) vs. 6/11 (54%)]. Oligogenic mutations were detected in 25.6% of the total cases and 35% of the mutated cases. Genetic basis was ascertained in 13 patients, reaching a diagnosis detection rate of 30%. In conclusion, genetic defects in dyshormonogenesis, mainly in DUOX2, were the main genetic cause of CH in the Chinese population. Oligogenicity is highly involved in CH pathogenesis and may thus be an important factor in common phenotypic variability observed in patients with CH.

Assessment of healthcare workers' behavior in implementing a newborn screening program for congenital hypothyroidism in Perak, Malaysia

Purpose

The aim of this study is to assess healthcare workers' behavior on the congenital hypothyroidism screening program implementation based on a framework protocol and its associated factors.

Design/methodology/approach

A cross-sectional study was conducted using the multistage random sampling method in recruiting health clinic workers and purposive sampling techniques for hospital workers. The demographics, providers' characteristic, occupational profile, attitude, perceived behavior control (PBC), knowledge, behavioral intention and adherence to protocol were gathered using validated and reliable self-administered questionnaires.

Findings

Partial intention to adhere to protocol was 25.7%. Weak attitude (adjusted odds ratio [AOR]: 5.48, 95% confidence interval [CI]: 3.32–9.06), low PBC score (AOR: 0.91, 95% CI: 0.86–0.95) and low knowledge score (AOR: 0.85, 95% CI: 0.75–0.96) were associated with partial intention to adhere to protocol. In the self-rated adherence assessment, 92.6% of participants from health clinics, 79.1% from pediatric and 61.1% from pathology were found not adhering to protocol. There was a significant association between intention and adherence to protocol.

Research limitations/implications

Documentations and observations in assessing program implementation were limited to perform in the present study. Using self-rated instruments and focusing on healthcare workers alone did not provide a comprehensive assessment.

Practical implications

Availability of a training module at site and regular refreshing course training should be made available to harness knowledge, attitude and behavioral perception in implementing the program activities.

Originality/value

Integrating the Logical Framework Approach in assessing program implementation and application of the Theory of Planned Behavior and Attitude, Subjective Norms, Self-Efficacy Model in this study were beneficial.

Growing up different in Neolithic China: A contextualised case study and differential diagnosis of a young adult with skeletal dysplasia

This paper presents a case study of a young adult from the late Neolithic Yangshao cultural period site (∼3300-2900 years BC) of Guanjia () located in Henan Province on the Central Plains of China, who has evidence for skeletal dysplasia characterised by proportional stunting of the long bones and a small axial skeleton, generalised osteopenia, and non-fusion of epiphyses. We provide a detailed differential diagnosis of skeletal dysplasia with paediatric onset and conclude that this is likely a form of hypopituitarism or hypothyroidism, an extremely rare finding within the archaeological context. This paper highlights the issues of distinguishing the forms of proportional dwarfism in palaeopathology because of the considerable variation in manifestation of these conditions. Finally, we assess whether there were any health and social implications for this person and community through the consideration of a bioarchaeology of care approach across the lifecourse, burial context, and information on social perceptions of 'difference' in the community. ：： （3300～2900）。，，，，。，，。。，。，、、""，。.

Investigating the incidence rate and geographical distribution of congenital hypothyroidism among neonates in Isfahan province using geographic information system (GIS) between 2002 and 2015

Background Congenital hypothyroidism (CH) is one of the main causes of mental retardation in neonates. The disease is associated with genetic, climatic and environmental factors. Accordingly, the present study was conducted to determine the incidence rate and correlation of geographic factors with CH in Isfahan province in order to explain the role of climatic factors in the incidence of disease in this province. Methods This cross-sectional study was conducted to determine the incidence rate and geographical distribution of CH in neonates born in the Isfahan province from the beginning of 2002 to the end of 2015. To estimate the geographic distribution, the ArcGIS software (version 10.3) was used and to investigate the relationship between geographical factors and CH, the Poisson regression test and dispersion diagrams were used. Data analysis was done using the SPSS16 software. Results According to the results of the screening of 1,006,404 neonates born in Isfahan, the mean incidence rate of CH in all infants was 2.3, and that in male and female infants was 2.39 and 2.2 per 1000 live births, respectively. There was a statistically significant correlation between the city of residence (p = 0.01), climatic conditions (p = 0.044), annual precipitation (p = 0.027), sunlight (p = 0.01) and CH. However, there was no significant relationship between the mean altitude above sea level (p = 0.6), land use (p = 0.4) and relative humidity (p = 0.24). Conclusions Based on the findings of this study, the incidence rate of CH in Isfahan province was higher than the average of the country. Moreover, among the geographical factors, climatic conditions, annual precipitation and sunlight were associated with CH.

DUOX2 and DUOXA2 Variants Confer Susceptibility to Thyroid Dysgenesis and Gland-in-situ With Congenital Hypothyroidism

Background: Thyroid dysgenesis (TD), which is caused by gland developmental abnormalities, is the most common cause of congenital hypothyroidism (CH). In addition, advances in diagnostic techniques have facilitated the identification of mild CH patients with a gland-in-situ (GIS) with normal thyroid morphology. Therefore, TD and GIS account for the vast majority of CH cases. Methods: Sixteen known genes to be related to CH were sequenced and screened for variations by next-generation sequencing (NGS) in a cohort of 377 CH cases, including 288 TD cases and 89 GIS cases. Results: In our CH cohort, we found that DUOX2 (21.22%) was the most commonly variant pathogenic gene, while DUOXA2 was prominent in TD (18.75%) and DUOX2 was prominent in GIS (34.83%). Both biallelic and triple variants of DUOX2 were found to be most common in children with TD and children with GIS. The most frequent combination was DUOX2 with DUOXA1 among the 61 patients who carried digenic variants. We also found for the first time that biallelic TG, DUOXA2, and DUOXA1 variants participate in the pathogenesis of TD. In addition, the variant p.Y246X in DUOXA2 was the most common variant hotspot, with 58 novel variants identified in our study. Conclusion: We meticulously described the types and characteristics of variants from sixteen known gene in children with TD and GIS in the Chinese population, suggesting that DUOXA2 and DUOX2 variants may confer susceptibility to TD and GIS via polygenic inheritance and multiple factors, which further expands the genotype-phenotype spectrum of CH in China.

Phenylketonuria incidence in China between 2013 and 2017 based on data from the Chinese newborn screening information system: a descriptive study

OBJECTIVE

This study examines the incidence and spatial clustering of phenylketonuria (PKU) in China between 2013 and 2017.

METHODS

Data from the Chinese Newborn Screening Information System were analysed to assess PKU incidence with 95% CIs by province, region and disease severity. Spatial clustering of PKU cases was analysed using global and local spatial autocorrelation analysis in the geographic information system.

RESULTS

The database contained 4925 neonates with confirmed PKU during the study period, corresponding to an incidence of 6.28 (95% CI: 6.11 to 6.46) per 100 000 neonates screened. Incidence was highest in the provinces of Gansu, Ningxia and Qinghai, where it ranged from 19.00 to 28.63 per 100 000 neonates screened. Overall incidence was higher in the northern part of the country, where classical disease predominated, than in the southern part, where mild disease predominated. PKU cases clustered spatially (global Moran's I=0.3603, Z=5.3097, p<0.001), and local spatial autocorrelation identified four northern provinces as high-high clusters (Gansu, Qinghai, Ningxia and Shanxi).

CONCLUSIONS

China shows an intermediate PKU incidence among countries, and incidence differs substantially among Chinese provinces and between northern and southern regions. Our results suggest the need to focus efforts on screening, diagnosing and treating PKU in high-incidence provinces.

Newborn screening in the developing countries

PURPOSE OF REVIEW

We review newborn screening (NBS) publications from the developing countries to identify global progress in improving child health.

RECENT FINDINGS

Many developing countries do not yet have national NBS. As infant mortality rates decline, NBS gains in public health priority. Local incidence and outcome data are used to persuade health officials to include screening in priority health spending. Congenital hypothyroidism is the most cost-effective screened condition in most countries. In sub-Saharan Africa, India and some parts of Asia, screening for hemoglobinopathies and glucose-6-dehydrogenase deficiency are also important. Expanded screening for metabolic conditions is most needed in areas of high consanguinity. Screening for hearing disorders and critical congenital heart defects is increasing globally. The largest birth cohorts are India and China, but only China has successful NBS. Reports from completed government research projects in India support initiation of NBS.

SUMMARY

Government activities around NBS are increasing in India and there is increased emphasis on pilot programs for sickle cell NBS in sub-Saharan Africa. Genetic counseling training in Asia and Africa is increasing and will be helpful as part of NBS. To build successful screening programs, partnerships among health professionals, parents, policy makers and industry stakeholders are essential.