Hair Mercury Levels and Their Relationship with Seafood Consumption among Preschool Children in Shanghai

Mercury is a global pollutant. Children are vulnerable to environmental toxicants. Seafood consumption is a major source of methylmercury exposure. In order to ascertain children's mercury exposure levels and study their relationship with seafood consumption, we conducted a cross-sectional study among preschool children in Shanghai. According to our data, the geometric mean of the mercury levels in children's hair was 191.9(95% CI: 181.8, 202.4) μg/kg. These results indicate that high income may be a predictor of elevated mercury levels in children's hair. Intake of marine fish, especially tuna and pomfret, was documented in our study and found to increase the risk of high mercury levels. Frequency of fish consumption was positively related with hair mercury levels. Our study is the first to provide baseline data for hair mercury concentration among preschool children in Shanghai.

Clinical Application of Chromosome Microarray Analysis in Han Chinese Children with Neurodevelopmental Disorders

Chromosome microarray analysis(CMA) is a cost-effective molecular cytogenetic technique that has been used as a first-line diagnostic test in neurodevelopmental disorders in the USA since 2011. The impact of CMA results on clinical practice in China is not yet well studied, so we aimed to better evaluate this phenomenon.We analyzed the CMA results from 434 patients in our clinic, and characterized their molecular diagnoses, clinical features, and follow-up clinical actions based on these results. The overall diagnostic yield for our patients was 13.6%(59 out of 434). This gave a detection rate of 14.7%for developmental delay/intellectual disability(DD/ID,38/259) and 12% for autism spectrum disorders(ASDs,21/175). Thirty-three recurrent(n≥2) variants were found, distributed at six chromosomal loci involving known chromosome syndromes(such as DiGeorge, Williams Beuren, and Angelman/Prader-Willi syndromes).The spectrum of positive copy number variants in our study was comparable to that reported in Caucasian populations, but with specific characteristics. Parental origin tests indicated an effect involving a significant maternal transmission bias to sons. The majority of patients with positive results(94.9%) had benefits, allowing earlier diagnosis(36/59), prioritized full clinical management(28/59), medication changes(7/59), a changed prognosis(30/59), and prenatal genetic counseling(15/59). Our results provide information on de novo mutations in Chinese children with DD/ID and/or ASDs. Our data showed that microarray testing provides immediate clinical utility for patients. It is expected that the personalized medical care of children with developmental disabilities will lead to improved outcomes in long-term developmental potential.We advocate using the diagnostic yield of clinically actionable results to evaluate CMA as it provides information of both clinical validity and clinical utility.

Associations between measures of pediatric human resources and the under-five mortality rate: a nationwide study in China in 2014

Background To quantify the associations between the under-five mortality rate(U5MR)and measures of pediatric human resources,including pediatricians per thousand children(PPTC)and the geographical distribution of pediatricians.Methods We analyzed data from a national survey in 2015-2016 in 2636 counties,accounting for 31 mainland provinces of China.We evaluated the associations between measures of pediatric human resources and the risk of a high U5MR(>18 deaths per 1000 live births)using logistic regression and restricted cubic spline regression models with adjustments for potential confounders.PPTC and pediatricians per 10,000 km^(2) were categorized into quartiles.The highest quartiles were used as reference.Results The median values of PPTC and pediatricians per 10,000 km^(2) were 0.35(0.20-0.70)and 150(50-500),respectively.Compared to the counties with the highest PPTC(≥0.7),those with the lowest PPTC(<0.2)had a 52% higher risk of a high U5MR,with an L-shaped relationship.An inverted J-shaped relationship was found that the risk of a high U5MR was 3.74[95%confidence interval(CI)2.55-5.48],3.07(95% CI 2.11-4.47),and 2.25 times(95% CI 1.52-3.31)higher in counties with<50,50-149,and 150-499 pediatricians per 10,000 km^(2),respectively,than in counties with≥500 physicians per 10,000 km^(2).The joint association analyses show a stronger association with the risk of a high U5MR in geographical pediatrician density than PPTC.Conclusion Both population and geographical pediatrician density should be considered when planning child health care services,even in areas with high numbers of PPTC.