Multiple studies have reported that individuals with low birth weights (LBW, <2500 g) have a lower intelligence quotient (IQ) than those with normal birth weights (NBW, ≥2500 g). Based on 57 eligible individual studies including 12,137 participants, we performed a meta-analysis to estimate the association between low birth weight and individuals’ IQ scores (IQs). The pooled weight mean difference (WMD) in IQs between NBW and LBW individuals was 10 (95% CI 9.26–11.68). The WMD was stable regardless of age. No publication bias was detected. The mean IQs of the extremely low birth weight (ELBW, <1000 g), very low birth weight (VLBW, 1000–1499 g), moderately low birth weight (MLBW, 1500–2499 g) and NBW individuals were 91, 94, 99 and 104, respectively. Additionally, the WMD in IQs with NBW were 14, 10 and 7 for ELBW, VLBW, and MLBW individuals, respectively. Two studies permitted estimates of the influence of social determinants of health to the discrepancy in IQs, which was 13%. Since IQ is inherited and influenced by environmental factors, parental IQs and other factors contribute to residual confounding of the results. As the conclusion was based on population studies, it may not be applicable to a single individual.

Increasing evidence suggests that abnormal synaptic function leads to neuronal developmental disorders and is an important component of the etiology of autism spectrum disorder (ASD). Neurexins are presynaptic cell-adhesion molecules that affect the function of synapses and mediate the conduction of nerve signals. Thus, neurexins are attractive candidate genes for autism. Since gene families have greater power to reveal genetic association than single genes, we designed this case-control study to investigate six genetic variants in three neurexin genes (NRXN1, NRXN2, and NRXN3) in a Chinese population including 529 ASD patients and 1,923 healthy controls. We found that two SNPs were significantly associated with ASD after false discovery rate (FDR) adjustment for multiple comparisons. The NRXN2 rs12273892 polymorphism T allele and AT genotype were significantly associated with increased risk of ASD (respectively: OR 5 1.328, 95% CI 5 1.133-1.557, P < 0.001; OR 5 1.528; 95% CI 5 1.249-1.868, P < 0.001). The dominant model showed the same association (OR 5 1.495, 95% CI 5 1.231-1.816, P < 0.001). The NRXN3 rs12879016 polymorphism played a significant role in ASD susceptibility under the dominant model (OR 5 0.747, 95% CI5 0.615-0.908, P 5 0.023), with the same trend detected for the G allele and GT genotype (respectively: OR 5 0.811, 95% CI 5 0.699-0.941, P 5 0.036; OR 5 0.755, 95% CI 5 0.615-0.928, P 5 0.035). In conclusion, this study supports the importance of two genetic variants in the neurexin gene family in ASD susceptibility in China. Autism Res 2018, 11: 37-43. V C 2017 International Society for Autism Research, Wiley Periodicals, Inc.Lay Summary: Autism spectrum disorder (ASD) is a neurodevelopmental disorder that is highly heritable, and studies have found a number of candidate genes that might contribute to ASD. Neurexins are presynaptic cell-adhesion molecules that affect the function of synapses and mediate the conduction of nerve signals, and they play an important role in normal brain development and become candidate genes for autism. The purpose of our study is to explore the association between variants of the neurexins gene family and ASD in a Chinese population through a case-control study.

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Several prenatal and perinatal factors have been found to be associated with developmental dyslexia (reading disorder) in alphabetic language. Given the absence of relevant studies of Chinese children, the present study tries to investigate these risk factors. A total of 45,850 students were recruited from grades three to six, from seven cities of Hubei province. Dyslexia in Chinese was diagnosed based on children’s clinical symptoms. The clinical symptoms of children’s reading performance were assessed by Dyslexia Checklist for Chinese Children (DCCC) and Pupil Rating Scale Revised Screening for Learning Disabilities (PRS) which were completed by parent/guardian and header teacher respectively. Chinese language exam was used to screen children with poor reading capacity. Questionnaires about prenatal and perinatal factors were completed by parent or guardian. Among the 34,748 eligible participants, 1,200 (3.45%) were diagnosed with dyslexia in Chinese. More boys suffered from dyslexia than the girls and the gender ratio was 3:1. Family history of neuropsychiatric diseases, maternal infectious diseases, difficult vaginal delivery, preterm birth, and neonatal asphyxia were found to increase the risk of developmental dyslexia in China. Closer longitudinal developmental monitoring and preventive measures should be taken for high risk children.

The interaction between soil property and soil microbial community in karst area still remains an open question. The characteristics of soil physicochemical properties and microbial community structure and their relationship under five vegetation succession stages (grassland, shrub land, secondary forest, plantation forest, and natural forest) at two soil depths (0–10 cm and 10–20 cm) were explored in a karst mountain ecosystem. We found that soil moisture content (SMC) and pH increased with soil depth across vegetation succession. The highest content of soil nutrients was found in the natural forest stage at both soil depths. The total PLFAs, the abundance of Gram-positive (GP) bacteria, actinomycetes (ACT), fungi, and arbuscular mycorrhizal fungi (AMF) were significantly (P < 0.05) related to variations with soil total carbon (TC) and total nitrogen (TN). Furthermore, the distribution of soil microbial community distinctly differed in vegetation succession both at two soil layers which was demonstrated by Principal-coordinates analysis. Redundancy analyses patterns indicated that soil TC and TN were positively related to cy19:0 and 10Me 16:0, but an opposite relationship with a15:0. Changes of soil microbial communities were significantly determined by vegetation succession, and soil microbial community structure can be a sensitive indicator to reflect the stabilization of karst mountain ecosystem, southwest of China.