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.
China/epidemiology* ; Cluster Analysis ; Congenital Hypothyroidism/epidemiology* ; Humans ; Incidence ; Infant, Newborn ; Retrospective Studies ; Spatial Analysis

BACKGROUND: Most cases with congenital hypothyroidism (CH) are usually sporadic, while about 20% of the cases are caused by genetic defects. Little information is available regarding the mutation incidence and genetic heterogeneity of CH in Koreans. We aimed to determine the mutation incidence of CH in newborn screenings (NBS) and to evaluate the frequency and spectrum of mutations underlying CH. METHODS: A total of 112 newborns with thyroid dysfunction were enrolled from 256,624 consecutive NBS. Furthermore, 58 outpatients with primary CH were added from an endocrine clinic. All coding exons of TSHR, PAX8, TPO, DUOX2, DUOXA2, and SCL5A5 were sequenced. RESULTS: The mutation incidence of CH was estimated to be 1 in 6,580 newborns. A total of 36 different mutations were identified in 53 cases. The overall mutation positive rate was 31%. The DUOX2 mutations were the most prevalent in both newborns and outpatients. Seven different recurrent mutations [p.G488R (n=13), p.A649E (n=3), p.R885Q (n=3), p.I1080T (n=2), and p.A1206T (n=2) in DUOX2; p.Y138X (n=9) in DUOXA2; and p.R450H (n=5) in TSHR) were identified as the mutations underlying CH. CONCLUSIONS: The mutation incidence of CH was considerably higher than expected in the Korean newborn population. This study revealed seven different recurrent mutations underlying CH. We conclude that DUOX2 mutations are a frequent cause of CH in the Korean population.
Asian Continental Ancestry Group/*genetics ; Child ; Child, Preschool ; Congenital Hypothyroidism/epidemiology/*genetics/pathology ; Exons ; Female ; Genetic Association Studies ; Genotype ; Humans ; Infant ; Infant, Newborn ; Male ; NADPH Oxidase/*genetics ; Polymorphism, Single Nucleotide ; Republic of Korea/epidemiology ; Sequence Analysis, DNA ; Thyrotropin/blood

OBJECTIVETo summarize and analyze neonatal screening results for congenital hypothyroidism (CH) in parts of Yunnan Province, China.

METHODSA total of 236 218 newborns (121 463 males and 114 755 females) who were born in Zhaotong City, Qujing City, Lijiang City, and Diqing Tibetan Autonomous Prefecture of Yunnan Province, China, between July 2012 and April 2014 were screened for CH. The original blood smear was re-tested if the thyroid stimulating hormone (TSH) level in heel blood was ≥8 μIU/L in the initial screening. The newborns with positive TSH results were called back for further diagnosis by measuring blood TSH and free thyroxine (FT4) levels.

RESULTSAmong 236 218 newborns, the pass rate of blood smears, re-acquisition rate of unqualified blood smears, and recall rate of suspected cases were 96.67%, 81.75%, and 73.02%, respectively. Sixty-six cases of CH were confirmed, among which 36 were male infants and 30 were female infants (P>0.05). The incidence rate of CH was 1/3 579, which was significantly lower than the national average rate (1/2 034; P<0.01). The gestational age of CH newborns was mostly between 37 to 42 weeks, and only 3% were born at a gestational age of >42 weeks. Most of the CH newborns had normal birth weight. The CH newborns with a body length of <50 cm accounted for 32%.

CONCLUSIONSThe incidence of CH in Yunnan Province is lower than the national average. There are no specific clinical features in CH newborns. The neonatal screening in Yunnan Province needs further improvement.

China ; epidemiology ; Congenital Hypothyroidism ; blood ; epidemiology ; Female ; Humans ; Infant, Newborn ; Male ; Neonatal Screening ; Thyrotropin ; blood

OBJECTIVETo understand the relationship between perinatal factors and congenital hypothyroidism (CH) and provide scientific evidence for the prevention of CH.

METHODSA case-control study was conducted among 125 neonates with CH (case group) and 375 neonates without CH (control group) in Fujian Neonatal Screening Center from January in 2012 to December in 2013. Univariate and multivariate logistic regression analysis were performed to identify the risk factors to CH during perinatal period.

RESULTSUnivariate logistic regression analysis indicated that compared with control group, gestational hypertension, gestational diabetes mellitus, gestational thyroid disease and older age of mother were the risk factors to CH, the difference was statistically significant (P < 0.05) and the risk of CH was higher in female babies, preterm babies, post-term babies low birth weight babies, macrosomia, twins, babies with birth defects and infection in cases group than those in control group, the difference was statistically significant (P < 0.05). Multivariate logistic analysis showed that older age of mother (OR = 2.518, 95% CI: 1.186-5.347), gestational diabetes mellitus (OR = 1.904, 95% CI: 1.190-3.045), gestational hypothyroidism or hyperthyroidism (OR = 12.883 and 30.797, 95% CI: 2.055-80.751 and 3.309-286.594), preterm birth (OR = 4.238, 95% CI: 1.269-14.155), and post-term birth (OR = 12.799, 95% CI: 1.257-130.327), low birth weight (OR = 3.505, 95% CI: 1.059-11.601), macrosomia (OR = 3.733, 95% CI: 1.415-9.851), twin or multiparous delivery (OR = 5.493, 95% CI: 1.701-17.735), birth defects (OR = 3.665, 95% CI: 1.604-8.371) and fetal distress (OR = 3.130, 95% CI: 1.317-7.440) were the high risk factors to CH (P < 0.05).

CONCLUSIONCH was correlated with mother's age, gestational diabetes, gestational thyroid disease as well as neonate's birth weight and gestational age, foetus number, fetal distress and other complicated birth defects at certain degree. More attention should be paid to perinatal care to reduce risk factors and the incidence of CH.

Birth Weight ; Case-Control Studies ; Congenital Hypothyroidism ; epidemiology ; Diabetes, Gestational ; epidemiology ; Female ; Gestational Age ; Humans ; Hypertension, Pregnancy-Induced ; epidemiology ; Incidence ; Infant, Newborn ; Infant, Premature ; Maternal Age ; Neonatal Screening ; Pregnancy ; Pregnancy Complications ; epidemiology ; Premature Birth ; Risk Factors ; Twins

Two trials of external quality assessment for conventional newborn screening tests for phenylketonuria, congenital hypothyroidism, galactosemia, maple syrup urine disease and homocytinuria and for the newborn screening tests using tandem mass spectrometry (MS/MS) were performed in 2009. Total 20 specimens were distributed to 13 laboratories. All the control materials were send as dried blood spots. The response rate was 100%. The mean, SD, CV, median and range were analyzed. In addition, two trials of external quality assessment for glycohemoglobin (HbA1c) were performed in 2009. Total 6 samples were distributed to 196 laboratories and the response rate was 97.2% (175/180) and 98.5% (193/196) in each trial. From this trial, we performed accuracy-based survey which used challenge specimens that were free from matrix effects and had target values traceable to certified reference material. Bias between each participants result and reference target value were evaluated.
Bias (Epidemiology) ; Congenital Hypothyroidism ; Galactosemias ; Humans ; Infant, Newborn ; Korea ; Maple Syrup Urine Disease ; Mass Screening ; Phenylketonurias ; Tandem Mass Spectrometry

OBJECTIVEThe retrospective study was carried out to investigate the nation-wide neonatal screening program in the past 22 years in China. This study aimed to summarize the experience, analyze the questions and concerns in the screening program.

METHODSAll data on the national neonatal screening in the past 22 years were from National Center for Clinical Laboratory. Study items included the development and mode of the program, screening method adopted as well as the clinical records of prevalence, treatment and follow-up etc.

RESULTSNeonatal screening has become universal since 1985 in China. There were three modes of screening and treatment. From 1985 to 2006, a total of 13,229,242 newborns were screened for congenital hypothyroidism (CH) and 6505 were diagnosed as CH at a prevalence of 49.2/100,000; a total of 13,666,750 newborns were screened for phenylketonuria (PKU), and 1,170 were diagnosed as PKU at a prevalence of 8.6/100,000. The prevalence of CH increased year by year and the western regions in China had a much higher prevalence. The prevalence of PKU was relatively more steady than that of CH in China.

CONCLUSIONSNeonatal screening is of paramount importance in preventing mental retardation and developmental delay after CH and PKU. It is necessary to attach more importance to increase the rate of coverage, screening and treatment, as well as social awareness of neonatal screening. It is important to focus on establishment of new screening techniques so as to improve the level of child health care in China.

China ; epidemiology ; Congenital Hypothyroidism ; epidemiology ; Humans ; Infant, Newborn ; Neonatal Screening ; Phenylketonurias ; epidemiology ; Prevalence ; Retrospective Studies

OBJECTIVETo investigate the correlation of congenital hypothyroidism (CH) with birth weight and gestational age in newborn infants.

METHODSThe screening of CH was conducted in all the live births in 2005 of Zhejiang Province, the blood samples were collected from heel stick. The thyroid stimulating hormone (TSH) was measured by time-resolved fluorescence immunoassay (TRFIA). If TSH was>9.0 mU/L, the infant was recalled for further examination.

RESULTSA total of 387,926 infants were screened in 2005, of whom 289 cases were identified with CH. The prevalence rate was 1/1,342. Among the 289 CH cases, the prevalence of premature infants, term infants and post term infants were 1/1,454, 1/1,469 and 1/246, respectively. The CH prevalence of post term infants was significantly higher than that in other two groups (P<0.01). The prevalence of low birth weight infants, normal weight infants and macrosomia was 1/575, 1/1,505 and 1/473, respectively. The prevalence of low birth weight infants and macrosomia was significantly higher than that of normal weight group (P<0.01).

CONCLUSIONThe prevalence of CH is associated with the birth weight and gestational age. To reduce the prevalence of CH in children, it is crucial to prevent post term, low birth weight, and macrosomia cases.

Birth Weight ; China ; epidemiology ; Congenital Hypothyroidism ; blood ; epidemiology ; physiopathology ; Female ; Gestational Age ; Humans ; Infant, Newborn ; Male ; Neonatal Screening ; Prevalence ; Thyrotropin ; blood

China ; epidemiology ; Congenital Hypothyroidism ; diagnosis ; epidemiology ; Humans ; Infant, Newborn ; Neonatal Screening

OBJECTIVETo analyze the data of screening for congenital hypothyroidism (CH) newborns in Zhejiang Province during 1999-2004.

METHODSThe dried blood samples were collected on filter paper. The levels of thyroid-stimulating hormone (TSH) were measured by time-resolved fluoroimmunoassay, and the serum levels of TSH, triiodothyronine (T(3)) and thyroxine (T(4)) were detected by chemiluminescence. Infants with CH confirmed by neonatal screening were treated with levothyroxine (L-T(4)) initiated with 4-6 g/kg x d(-1 )for 2-3 years. Growth, development and intelligence status, scintigraphy or ultrasonography of thyroid, and bone age were investigated to evaluate the efficacy of therapy during follow-ups.

RESULTA total of 1112784 neonates were screened for CH during 1999-2004 with a coverage rate of 63.5%. Of the 6750 suspected CH cases, 6335 (93.8%) were recalled. 764 cases of CH were confirmed with an average incidence rate of 1 case CH per 1457 newborns (1/1457). 244 of 764 patients were followed-up for more than 1.5-2 years. All of them received thyroid by scintigraphy or ultrasonography. Among them 189 cases were found with normal gland, 35 with hypogenetic gland, 11 with ectopic gland, and the remaining 9 didn't show any image of thyroid. The average score of development quotient (DQ) was 106. 9. Among them, the DQ score was less than 85 in 2 cases, less than 90 in 9 cases, less than 100 in 28 cases, and in 68 cases the DQ was greater than 100. The bone age of 122 CH infants was evaluated with the X-ray radiography. In 90 cases of them,the bone age was normal, and 32 cases had progressed from development delay to normal. The height and weigh measured in all 106 cases had reached the related age criteria. The evaluation indicated that 55 cases were found with primary CH, 169 with temporary CH and 20 with subclinical CH.

CONCLUSIONNeonatal screening for CH and regular treatment for CH patients are important for attaining normal body development and intelligence development of patients.

China ; epidemiology ; Congenital Hypothyroidism ; epidemiology ; prevention & control ; Female ; Humans ; Incidence ; Infant, Newborn ; Male ; Neonatal Screening ; Thyrotropin ; blood ; Thyroxine ; blood ; Triiodothyronine ; blood

OBJECTIVESTo summarize neonatal screening for phenylketonuria (PKU) and congenital hypothyroidism (CH) in China, to further clarify incidence of the two kinds of diseases in newly-born babies, and to explore issues in neonatal screening and their solutions.

METHODSNeonatal screening for PKU and CH was conducted by 39 neonatal screening centers all over the country, sponsored by the Group of Neonatal Screening, Chinese Society of Child Health Care, Chinese Preventive Medical Association and the Center for Neonatal Screening Quality Control Laboratory, National Center for Clinical Laboratories (NCCL). In each infant a heel prick blood sample was collected at 72 hours postnatal onto standard filter paper. PKU was screened by bacterial inhibition assay and fluorometric method, and CH was screened by TSH measurement by time-resolved fluorescence immunoassay (TRFIA), fluorescence enzyme immunoassay (FEIA) and enzyme immunoassay (EIA).

RESULTSFrom 1985 to 2001 in China, totally of 5 817 280 newborns were screened for PKU, 522 cases of PKU detected with an incidence of 1:11 144, and 5 524 019 newborns were screened for CH, 1 836 cases of CH detected with an incidence of 1:3 009. Annual average number of newborns screened for congenital genetic diseases was increased by 45.5% in recent six years.

CONCLUSIONSNeonatal screening was developed quickly in China in recent years, especially in some developed cities, such as Shanghai with a coverage of 98.3% in 2001. But, its coverage was about only 10% in China as a whole. In development of neonatal screening, it is necessary to attach more importance to quality of screening and increasing coverage of screening, as well as gradual development of new screening techniques for other neonatal preventable diseases, in addition to PKU and CH, and their application, and improvement of level of child health care in China.

China ; epidemiology ; Congenital Hypothyroidism ; Fluorescence Polarization Immunoassay ; Fluorometry ; Humans ; Hypothyroidism ; epidemiology ; Immunoenzyme Techniques ; Infant, Newborn ; Neonatal Screening ; Phenylketonurias ; epidemiology ; Thyrotropin ; blood