[Progress in research of risk prediction of non-syndromic oral clefts using genetic information].

Non-syndromic oral cleft (NSOC), a common birth defect, remains to be a critical public health problem in China. In the context of adjustment of childbearing policy for two times in China and the increase of pregnancy at older childbearing age, NSOC risk prediction will provide evidence for high-risk population identification and prenatal counseling. Genome-wide association study and second generation sequencing have identified multiple loci associated with NSOC, facilitating the development of genetic risk prediction of NSOC. Despite the marked progress, risk prediction models of NSOC still faces multiple challenges. This paper summarizes the recent progress in research of NSOC risk prediction models based on the results of extensive literature retrieval to provide some insights for the model development regarding research design, variable selection, model-build strategy and evaluation methods.

[Prevalence of mountain-zoonotic type visceral leishmaniasis in Yangquan City of Shanxi Province from 2015 to 2020].

OBJECTIVE: To investigate the prevalence of mountain-type zoonotic visceral leishmaniasis (MT-ZVL) in Yangquan City, Shanxi Province from 2015 to 2020, so as to provide the scientific evidence for formulating the MT-ZVL control strategy. METHODS: The epidemiological data pertaining to MT-ZVL cases in Yangquan City from 2015 to 2020 were collected and descriptively analyzed. A Joinpoint regression model was created to analyze the trend in the MT-ZVL incidence in Yangquan City from 2015 to 2020 using annual percent change (APC). The sandflies surveillance data and the prevalence of Leishmania infections in dogs were collected in Yangquan City in 2020, and the regional distribution of sandflies density and sero-prevalence of Leishmania infections in dogs were calculated. In addition, the associations of sandflies density and sero-prevalence of Leishmania infections in dogs with the incidence of human MT-ZVL were examined using the linear correlation analysis. RESULTS: A total of 162 MT-ZVL cases were reported in Yangquan City, Shanxi Province from 2015 to 2020, with annual mean incidence of 1.9/105, and there were 4, 7, 16, 27, 33 cases and 75 cases with MT-ZVL reported from 2015 to 2020, appearing a tendency towards a rapid rise (APC = 72.79%, t = 11.10, P < 0.01). MT-ZVL cases were reported across the five counties (districts) of Yangquan City, and the cases predominantly occurred in Jiaoqu District (35.2%, 57/162) and Pingding County (33.3%, 54/162). MT-ZVL cases were predominantly detected in residents at ages of 15 years and older (71.6%, 116/162) and at ages of 0 to 2 years (22.2%, 36/162), with farmers (37.4%, 61/162) and diaspora children (24.5%, 40/162) as predominant occupations. The mean density of Phlebotomus chinensis was 6.3 sandflies per trap per night in Yangquan City from during the period from May to September, 2020, with the highest density observed in Jiaoqu District (12.6 sandflies per trap per night) and the lowest in Yuxian County (1.1 sandflies per trap per night), and there was a region-specific mean density of Ph. chinensis in Yangquan City (H = 17.282, P < 0.01). The sero-prevalence of serum anti-Leishmania antibody was 7.4% (2 996/40 573) in domestic dogs in Yangquan City, with the highest sero-prevalence seen in Jiaoqu District (16.6%, 1 444/8 677), and the lowest in Yuxian County (2.3%, 266/11 501), and there was a region-specific sero-prevalence rate of anti-Leishmania antibody in domestic dogs in Yangquan City (χ2 = 1 753.74, P < 0.01). The sero-prevalence of anti-Leishmania antibody was significantly higher in stray dogs (20.0%, 159/794) than in domestic dogs (χ2 = 176.63, P < 0.01). In addition, there were significant associations among the sandflies density, sero-prevalence of anti-Leishmania antibody in domestic dogs and the incidence of human MT-ZVL (r = 0.832 to 0.870, all P values < 0.05). CONCLUSIONS: The prevalence of MT-ZVL appeared a tendency towards a rapid rise in Yangquan City from 2015 to 2020, and systematic interventions are urgently needed for MT-ZVL control.

[Exploring the association between de novo mutations and non-syndromic cleft lip with or without palate based on whole exome sequencing of case-parent trios].

OBJECTIVE: To explore the association between de novo mutations (DNM) and non-syndromic cleft lip with or without palate (NSCL/P) using case-parent trio design. METHODS: Whole-exome sequencing was conducted for twenty-two NSCL/P trios and Genome Analysis ToolKit (GATK) was used to identify DNM by comparing the alleles of the cases and their parents. Information of predictable functions was annotated to the locus with SnpEff. Enrichment analysis for DNM was conducted to test the difference between the actual number and the expected number of DNM, and to explore whether there were genes with more DNM than expected. NSCL/P-related genes indicated by previous studies with solid evidence were selected by literature reviewing. Protein-protein interactions analysis was conducted among the genes with protein-altering DNM and NSCL/P-related genes. R package "denovolyzeR" was used for the enrichment analysis (Bonferroni correction: P=0.05/n, n is the number of genes in the whole genome range). Protein-protein interactions among genes with DNM and genes with solid evidence on the risk factors of NSCL/P were predicted depending on the information provided by STRING database. RESULTS: A total of 339 908 SNPs were qualified for the subsequent analysis after quality control. The number of high confident DNM identified by GATK was 345. Among those DNM, forty-four DNM were missense mutations, one DNM was nonsense mutation, two DNM were splicing site mutations, twenty DNM were synonymous mutations and others were located in intron or intergenic regions. The results of enrichment analysis showed that the number of protein-altering DNM on the exome regions was larger than expected (P < 0.05), and five genes (KRTCAP2, HMCN2, ANKRD36C, ADGRL2 and DIPK2A) had more DNM than expected (P < 0.05/(2×19 618)). Protein-protein interaction analysis was conducted among forty-six genes with protein-altering DNM and thirteen genes associated with NSCL/P selected by literature reviewing. Six pairs of interactions occurred between the genes with DNM and known NSCL/P-related genes. The score measuring the confidence level of the predicted interaction between RGPD4 and SUMO1 was 0.868, which was higher than the scores for other pairs of genes. CONCLUSION: Our study provided novel insights into the development of NSCL/P and demonstrated that functional analyses of genes carrying DNM were warranted to understand the genetic architecture of complex diseases.

[Association study between haplotypes of WNT signaling pathway genes and nonsyndromic oral clefts among Chinese Han populations].

OBJECTIVE: To explore whether WNT signaling pathway genes were associated with non-syndromic oral clefts (NSOC) based on haplotypes analyses among 1 008 Chinese NSOC case-parent trios. METHODS: The genome-wide association study (GWAS) data of 806 Chinese non-syndromic cleft lip with or without cleft palate (NSCL/P) trios and 202 Chinese non-syndromic cleft palate (NSCP) case-parent trios were drawn from the International Consortium to Identify Genes and Interactions Controlling Oral Clefts (ICOCs) study GWAS data set, whose Chinese study population were recruited from four provinces in China, namely Taiwan, Shandong, Hubei, and Sichuan provinces. The process of DNA genotyping was conducted by the Center for Inherited Disease Research in the Johns Hopkins University, using Illumina Human610-Quad v.1_B Bead Chip. The method of sliding windows was used to determine the haplotypes for analyses, including 2 SNPs haplotypes and 3 SNPs haplotypes. Haplotypes with a frequency lower than 1% were excluded for further analyses. To further assess the association between haplotypes and NSOC risks, and the transmission disequilibrium test (TDT) was performed. The Bonferroni method was adopted to correct multiple tests in the study, with which the threshold of statistical significance level was set as P < 0.05 divided by the number of tests, e.g P < 3.47×10-4 in the current stu-dy. All the statistical analyses were performed by using plink (v1.07). RESULTS: After quality control, a total of 144 single nucleotide polymorphisms (SNPs) mapped in seven genes in WNT signaling pathway were included for the analyses among the 806 Chinese NSCL/P trios and 202 Chinese NSCP trios. A total of 1 042 haplotypes with frequency higher than 1% were included for NSCL/P analyses and another 1 057 haplotypes with frequency higher than 1% were included for NSCP analyses. Results from the TDT analyses showed that a total of 69 haplotypes were nominally associated with the NSCL/P risk among Chinese (P < 0.05). Another 34 haplotypes showed nominal significant association with the NSCP risk among Chinese (P < 0.05). However, none of these haplotypes reached pre-defined statistical significance level after Bonferroni correction (P>3.47×10-4). CONCLUSION: This study failed to observe any statistically significant associations between haplotypes of seven WNT signaling pathway genes and the risk of NSOC among Chinese. Further studies are warranted to replicate the findings here.

[Development and evaluation of a machine learning prediction model for large for gestational age].

Objective: To develop and validate a useful predictive model for large gestational age (LGA) in pregnancy using a machine learning (ML) algorithm and compare its performance with the traditional logistic regression model. Methods: Data were obtained from the National Free Preconception Health Examination Project in China, carried out in 220 counties of 31 provinces from 2010 to 2012, covering all rural couples with a planned pregnancy. This study included all teams of childbearing age who delivered newborns within 24-42 weeks of gestational age and their newborns. Ten different ML algorithms were used to establish LGA prediction models, and the prediction performance of these models was evaluated. Results: A total of 104 936 newborns were included, including 54 856 boys (52.3%) and 50 080 girls (47.7%). The incidence of LGA was 11.7% (12 279). The imbalance between the two groups was addressed by the under- sampling technique, after which the overall performance of the ML models was significantly improved. The CatBoost model achieved the highest area under the receiver-operating-characteristic curve (AUC) value of 0.932. The logistic regression model had the worst performance, with an AUC of 0.555. Conclusions: In predicting the risk for LGA in pregnancy, the ML algorithms outperform the traditional logistic regression method. Compared to other ML algorithms, CatBoost could improve the performance, and it deserves further investigation.

[Progress in genetic epidemiology of non-syndromic cleft palate only].

One of the most common birth defects is cleft palate only (CPO) of which non-syndromic cleft palate only (NSCPO) accounts for 50%. NSCPO is a complex disease where multiple genes and environmental factors contribute to its risk. Unlike non-syndromic cleft lip with or without cleft palate (NSCL/P), previous genome-wide association studies only identified a few common genetic variations achieving genome-wide significance. This review summarizes the recent findings on genetic epidemiology of NSCPO. According to the current evidence, the candidate genes are divided into three categories: candidate genes with strong evidence, candidate genes with suggestive evidence, and candidate genes with inadequate evidence. The findings of epigenetic studies, the next generation sequencing studies, interaction analysis on NSCPO are also reviewed.

[Analysis of diagnosis, treatment and risk classification of blunt thoracic aortic injury].

Objective: Propose a new risk classification system for blunt thoracic aortic injury and explore its treatment strategies. Methods: After the retrospective analysis of clinical data from 68 patients with blunt thoracic aortic injury in the First Affiliated Hospital of Zhengzhou University from November 2016 to October 2020, there were 56 males and 12 females, among these patients, the median age was 45(21-69). According to the degree of aortic injury and the combined injury, the patients were scored for aortic injury, and the risk of the patients were graded into following three types: low-risk group (score ≤ 2 points) 12 cases, intermediate-risk group (3 points ≤ score ≤ 5 points) 41 cases, high-risk group (score ≥ 6 points) 15 cases. Analyzing the effects of treatments received by patients in different grades on the prognosis. Patients were followed up through hospitalization or outpatient clinics at 1, 3, 6, 12 months after surgery and every year thereafter. Results: Of the 68 patients, 21 received non-surgical treatment and 47 received surgical repair, including 6 open surgery and 41 thoracic aortic endovascular repair. There were 16 cases of emergency operation and 31 cases of delayed operation. Twelve low-risk patients were treated with non-surgical treatment, and only 1 patient died of lung infection, with a mortality rate of 8.3% (1/12). There were 8 deaths in 41 moderate-risk patients, with a mortality rate of 19.5% (8/41), and the aortic-related mortality rate was 9.8% (4/41), and the operative mortality rate was 10.8% (4/37). The total mortality of 15 high-risk patients was 40% (6/15), and the aortic-related mortality rate was 30.0% (5/15), and the mortality rate of surgical patients was 10% (1/10). During the follow-up period of 5 to 52 months, no deaths occurred outside the hospital. According to the risk grading, there were significant differences in the aortic-related mortality of each grade (χ²=7.840, P=0.020). During the follow-up of 5-52 months, 1 case had type Ⅰ endoleak, 1 case of cerebral infarction, and 1 case of acute renal failure. Conclusion: According to the patient's degree of aortic injury and combined injury, the risk classification helps to choose the appropriate treatment.

Abnormalities of the default-mode network homogeneity and executive dysfunction in people with first-episode, treatment-naive left temporal lobe epilepsy.

OBJECTIVE: Converging evidence has demonstrated that there is aberrant connectivity of the default-mode network (DMN) in left temporal lobe epilepsy (lTLE) yet changes in the network homogeneity (NH) of the DMN in people with first-episode, treatment-naive lTLE remains unclear. In this study, we used an NH method to investigate the NH of the DMN in people with first-episode, treatment-naive, lTLE, at rest. PATIENTS AND METHODS: We collected resting-state functional magnetic resonance imaging (rs-fMRI), and attention network test (ANT) data from 43 people with lTLE and 42well-matched, healthy control subjects. An NH approach was used to analyze the data. RESULTS: People with lTLE have decreased NH in the right inferior temporal gyrus (ITG) and the left middle temporal lobe (MTG), and increased NH in the bilateral precuneus (PCu) and right inferior parietal lobe (IPL), as compared with the controls. We also found that people with lTLE had a longer executive control reaction time (RT). No significant correlations were found between abnormal NH values and clinical variables in the subjects. CONCLUSIONS: These findings suggest that abnormal NH of the DMN exists in lTLE subjects and highlight the significance of the DMN in the pathophysiology of cognitive problems occurring in lTLE.

[Exploring parent-of-origin effects for non-syndromic cleft lip with or without cleft palate on PTCH1, PTCH2, SHH, SMO genes in Chinese case-parent trios].

OBJECTIVE: Non-syndromic cleft lip with or without cleft palate (NSCL/P) is a common birth defect, affecting 1.4 per 1 000 live births, and multiple genetic and environmental risk factors influencing its risk. All the known genetic risk factors accounted for a small proportion of the heritability. Several authors have suggested parent-of-origin effects (PoO) may play an important role in the etiology of this complex and heterogeneous malformation. To clarify the genetic association between PTCH1, PTCH2, SHH and SMO in hedgehog (HH) pathway and NSCL/P, as well as testing for potential PoO effects in Chinese case-parent trios. METHODS: We tested for transmission disequilibrium tests (TDT) and PoO effects using 83 common single nucleotide polymorphic (SNP) markers of HH pathway genes from 806 NSCL/P case-parent trios. These trios were drawn from an international consortium established for a genome-wide association studies (GWAS) of non-syndromic oral clefts of multiple ethnicities. DNA samples were collected from each trio. Single marker and haplotype based analysis were performed both in TDT tests and PoO effects. SNPs were excluded if they (ⅰ) had a call rate of < 95%, (ⅱ) had a minor allele frequency (MAF) of < 0.05, (ⅲ) had Mendelian errors over all trios of >5%, (ⅳ) had a genotype distribution in the parents that deviated from the Hardy-Weinberg equilibrium (HWE) (P < 0.000 1). The process was done using Plink (version 1.07, http://pngu.mgh.harvard.edu/~purcell/plink/data.shtml). TDT test was performed in Plink v1.07. A log-linear model was used to explore PoO effects using Haplin v6.2.1 as implemented in R package v3.4.2. Significance level was assessed using the Bonferroni correction. RESULTS: A total of 18 SNPs were dropped due to low MAF, thus leaving 65 SNPs available for the analysis. Thus the Bonferroni threshold was 7.7×10-4 (0.05/65). Nominal significant association with NSCL/P was found at a SNP (rs4448343 in PTCH1, P=0.023) and six haplotypes (rs10512249-rs4448343, rs1461208-rs7786445, rs10512249-rs4448343, rs16909865-rs10512249-rs4448343, rs1461208-rs7786445-rs12698335, and rs288756-rs288758-rs1151790, P < 0.05). A total of six haplotypes (rs288765-rs1233563, rs12537550-rs11765352, rs872723-rs288765-rs1233563, rs288765-rs1233563-rs288756, rs6459952-rs12537550-rs11765352, and rs12537550-rs11765352-rs6971211) showed PoO effect (P < 0.05). None of the results remained significant after the Bonferroni correction (P>7.7×10-4). CONCLUSION: Neither significant association between SNPs within HH pathway and the risk of NSCL/P nor PoO effects was seen in this study.

[Evaluating the effect of WNT pathway genes considering interactions on the risk of non-syndromic oral clefts among Chinese populations].

OBJECTIVE: In this study, we used genome-wide association study (GWAS) data to explore whether WNT pathway genes were associated with non-syndromic oral clefts (NSOC) considering gene-gene interaction and gene-environment interaction. METHODS: We conducted the analysis using 806 non-syndromic cleft lip with or without cleft palate (NSCL/P) case-parent trios and 202 non-syndromic cleft palate (NSCP) case-parent trios among Chinese populations selected from an international consortium established for a GWAS of non-syndromic oral clefts. Genotype data and maternal environmental exposures were collected through DNA samples and questionnaires. Conditional Logistic regression models were adopted to explore gene-gene interaction and gene-environment in teraction using trio package in R software. The threshold of significance level was set as 3.47×10-4 using Bonferroni correction. RESULTS: A total of 144 single nucleotide polymorphisms (SNPs) in seven genes passed the quality control process in NSCL/P trios and NSCP trios, respectively. Totally six pairs of SNPs interactions showed statistically significant SNP-SNP interaction (P < 3.47×10-4) after Bonferroni correction, which were rs7618735 (WNT5A) and rs10848543 (WNT5B), rs631948 (WNT11) and rs556874 (WNT5A), and rs631948 (WNT11) and rs472631 (WNT5A) among NSCL/P trios; rs589149 (WNT11) and rs4765834 (WNT5B), rs1402704 (WNT11) and rs358792 (WNT5A), and rs1402704 (WNT11) and rs358793 (WNT5A) among NSCP trios, respectively. In addition, no significant result was found for gene-environment interaction analysis in both of the NSCL/P trios and NSCP trios. CONCLUSION: Though this study failed to detect significant association based on gene-environment interactions of seven WNT pathway genes and the risk of NSOC, WNT pathway genes may influence the risk of NSOC through potential gene-gene interaction.

A torque type full tensor gravity gradiometer based on a flexure-strip suspension.

Full tensor gravity gradiometers based on accelerometer pair combination are widely employed in earth resource explorations using gravity gradient measurements. However, the extremely high requirements of accelerometer dynamic range and the scale factor consistency of accelerometer pairs are the two main limitations to further improve their performances. In order to overcome these two extreme challenges, the torque type gravity gradiometer based on the Etövös torsion balance pendulum is re-considered. In this paper, an improved torque type full tensor gravity gradiometer with a flexure-strip suspension is proposed, which balances the mechanical sensitivity and the response time. The proposed gradiometer can be used to measure the full tensor gravity gradient by observing angle variations at three azimuths. The principle and feasibility of the torque type full tensor gravity gradiometer based on a flexure-strip suspension are introduced, and the main noise sources including mechanical thermal noise, position sensing noise, and readout noise are analyzed. A prototype gravity gradiometer with a designed resolution of 2 E/Hz1/2 at 0.1 Hz is constructed (1 E = 10-9/s2), and the experimental results indicate that its resolution comes to 3 E/Hz1/2 at 0.1 Hz, which is mainly limited by the seismic noise. This type of gravity gradiometer can be further improved due to its high potential resolution and independence of matching combination requirement, which allows it to be applied in next generation gravity resource exploration.

[Study regarding the parent-of-origin effect of WNT pathway genes on non-syndromic cleft lip with or without cleft palate among the Chinese population].

Objective: Non-syndromic cleft lip with or without cleft palate (NSCL/P) is a common birth defect with its genetic evidence widely explored. This study explored the potential the parent-of-origin (PoO) effect of WNT pathway on the risks of NSCL/P, using a case-parent trio design. Methods: Data on the single nucleotide polymorphism (SNP) of WNT genes were selected from a genome-wide association study (GWAS). A total of 806 Chinese non-syndromic cleft lip patients, with or without cleft palate (NSCL/P) case-parent trios, were gathered from an international consortium. PoO effect of WNT pathway genes and its haplotypes were explored by log-linear models. Additional Wald tests were performed to assess: a) the heterogeneity of PoO effect between different maternal exposures, b) the interaction between PoO effect, c) maternal exposure to environmental tobacco smoke (ETS), and d) multivitamin supplementation during pregnancy. The threshold for statistical significance was adjusted as 3.47×10(-4), according to Bonferroni correction. Results: After quality control, a total of 144 SNPs within seven genes were included for analyses, among which 8 SNPs were of potential PoO effect (P<0.05). However, none of them achieved the statistical significance after Bonferroni correction. The haplotype rs4074668-rs12725747 (T-A) on WNT9A showed significant PoO effect, based on the haplotype test for PoO (P=2.74×10(-4)). In addition, no statistically significant interaction was found in further exploration of this haplotype under environmental exposures as ETS or multivitamin supplementation. Conclusions: Genes in the WNT pathway may influence the NSCL/P risks through the potential PoO effect. Particularly, the haplotype rs4074668-rs12725747 (T-A) on WNT9A presented significant PoO effect on NSCL/P, statistically. From this current study, findings on WNT pathway related risks among the NSCL/P, need to be further validated by independent samples in the future.

[Analysis of single-nucleotide polymorphism of Sonic hedgehog signaling pathway in non-syndromic cleft lip and/or palate in the Chinese population].

OBJECTIVE: To study the relationship between Sonic hedgehog (Shh) associated single-nucleotide polymorphism (SNP) and non-syndromic cleft lip and/or palate (NSCL/P), and to explore the risk factors of cleft lip and/or palate. Many studies suggest that the pathogenesis of NSCL/P could be related to genes that control early development, in which the Shh signaling pathway plays an important role. METHODS: Peripheral blood was collected from 197 individuals (100 patients with NSCL/P and 97 healthy controls). Haploview software was used for haplotype analysis and Tag SNP were selected, based on the population data of Han Chinese in Beijing of the international human genome haplotype mapping project. A total of 27 SNP were selected for the 4 candidate genes of SHH, PTCH1, SMO and GLI2 in the Shh signaling pathway. The genotypes of 27 SNP were detected and analyzed by Sequenom mass spectrometry. The data were analyzed by chi-squared test and an unconditional Logistic regression model. RESULTS: The selected SNP basically covered the potential functional SNP of the target genes, and its minimum allele frequency (MAF) was >0.05: GLI2 73.5%, PTCH1 91.0%, SMO 100.0%, and SHH 75.0%. It was found that the genotype frequency of SNP (rs12674259) located in SMO gene and SNP (rs2066836) located in PTCH1 gene were significantly different between the NSCL/P group and the control group. Linkage disequilibrium was also found on 3 chromosomes (chromosomes 2, 7 and 9) where the 4 candidate genes were located. However, in the analysis of linkage imbalance haplotype, there was no significant difference between the disease group and the control group. CONCLUSION: In China, NSCL/P is the most common congenital disease in orofacial region. However, as it is a multigenic disease and could be affected by multiple factors, such as the external environment, the etiology of NSCL/P has not been clearly defined. This study indicates that Shh signaling pathway is involved in the occurrence of NSCL/P, and some special SNP of key genes in this pathway are related to cleft lip and/or palate, which provides a new direction for the etiology research of NSCL/P and may provide help for the early screening and risk prediction of NSCL/P.

[Exploring the association between SPRY gene family and non-syndromic oral clefts among Chinese populations using data of a next-generation sequencing study].

OBJECTIVE: To explore the association between SPRY gene family and the risk of non-syndromic oral clefts among Chinese populations, in respect of single nucleotide polymorphisms (SNPs) association and parent-of-origin effects. METHODS: Based on case-parent design, this study used the data of SPRY gene family in a next generation sequencing study of 183 non-syndromic cleft lip with or without cleft palate (NSCL/P) case-parent trios (549 participants) recruited from 2016 to 2018, to analyze the effects of SNP association and parent-of-origin. The sequencing study adopted a two-stage design. In the first stage, whole exome sequencing was conducted among 24 NSCL/P trios with family history to explore potential signals. Then in the second stage, another 159 NSCL/P trios were used as validation samples to verify the signals found in the first stage. The data of general information, disease features and parental environmental exposures for participants were collected through questionnaires. Blood samples were collected from each participant for DNA extraction and sequencing. Transmission disequilibrium tests (TDT) were conducted to test for the association between SNPs and NSCL/P, while Z score tests were applied to analyze parent-of-origin effects. The analyses were performed using Plink (v1.07). TRIO package in R (v3.5.1). Besides, famSKAT analyses were conducted in the first stage to combine the effect of SNPs located on the same gene, using famSKAT package in R(V3.5.1). Bonferroni method was adopted to correct multiple tests in the second stage. RESULTS: Twenty-two SNPs in SPRY gene family were included for analyses after the quality control process in the first stage. Based on the variants annotation, functional prediction and statistical analysis, rs1298215244 (SPRY1) and rs504122 (SPRY2) were included in the second verification stage. TDTs in the verification stage revealed that rs1298215244: T>C, rs504122: G>C and rs504122: G>T were associated with the risk of NSCL/P after Bonferroni corrections, where rs504122: G>T was a rare variation. Although the test for parent-of-origin effect of rs1298215244: T>C reached nominal significance level, no SNP showed significant association with NSCL/P through parent-of-origin effect after Bonferroni corrections. CONCLUSION: This study found that SNPs (including both common and rare variants) among the SPRY gene family were associated with the risk of NSCL/P among Chinese populations. This study failed to detect parent-of-origin effects among the SPRY gene family.

[Progress in next-generation sequencing research of non-syndromic oral clefts].

Non-syndromic oral clefts (NSOC) are among the most common birth defects. The prevalence of NSOC is 1.13-1.30 per 1 000 live births in China, which is higher than those in other major ethnic groups. The etiology of NSOC is complex and heterogeneous, which involves both genetic and environmental risk factors. Although genome-wide association studies have identified a number of risk loci, these loci can only account for a small proportion of the heritability of NSOC. The next-generation sequencing research provides new ideas for further exploring the genetic risk factors of NSOC. This paper summaries the progress in the next-generation sequencing research of NSOC.

Evidence of interaction between genes in the folate/homocysteine metabolic pathway in controlling risk of non-syndromic oral cleft.

OBJECTIVE: Little consistent evidence is available for the association between the risk of non-syndromic cleft lip with or without cleft palate (NSCL/P) and any of the individual genes in the folate/homocysteine metabolic pathway. We investigated the genes in the folate pathway to further clarify its potential influence on the risk of NSCL/P considering gene-gene (G×G) interaction. SUBJECTS AND METHODS: We selected markers in 18 genes from the pathway and applied Cordell's method to test for G×G interaction using 1,908 NSCL/P case-parent trios ascertained in an international consortium where a genomewide association study (GWAS) of oral clefts was conducted. RESULTS: We found intriguing signals among Asian and European ancestry groups for G×G interaction between markers in betaine-homocysteine methyltransferase gene (BHMT/BHMT2) and dimethylglycine dehydrogenase gene (DMGDH) attaining genomewide significance. In the pooled data, the top significant interaction was found between rs13158309 (BHMT) and rs10514154 (DMGDH, p = 1.45 × 10-12 ). CONCLUSIONS: Our study illustrated the importance of taking into account potential G×G interaction for genetic association analysis in NSCL/P, and this study suggested both BHMT/BHMT2 and DMGDH should be considered as candidate genes for NSCL/P in future studies.

[Seroepidemiological investigation of hepatitis C virus in Zhejiang Province: a hospital-based study].

Objective: To study serum HCV antibody (anti-HCV) with geographic distribution characteristics in Zhejiang Province. Methods: A stratified random cluster sampling method was used. Serum samples of the surveyed population were collected from selected hospitals, anti-HCV antibodies were examined, then hepatitis C infection rates among different genders, regions and age groups were analyzed. The anti-HCV rate was compared using the χ (2) test. Results: The average anti-HCV positive rate in Zhejiang Province was 0.24% [95% confidence interval (CI): 0.16% ~ 0.32%]. The antibody positive rate in the plain area was 0.32% (95% CI: 0.19% ~ 0.45%), which was significantly higher than the coastal islands 0.05%(95% CI: 0.00% ~ 0.12%, χ (2) = 7.638, P < 0.05). There was no significant difference between plain area and hilly area 0.22% (95% CI: 0.03% - 0.41%). There was no statistically significant difference in anti-HCV positive rates between males and females (χ (2) = 2.238, P = 0.135). The highest positive rate of anti-HCV (0.93%) was in the population aged 56-60 years and the lowest in the population aged less than 20 years. Anti-HCV positive rate of all age groups in 2017 was lower than that of 2006 seroepidemiological study of hepatitis C. Conclusion: Zhejiang Province is a region with low anti-HCV positive rate and the disease prevalence further reduced than 10 years ago. The positive rate of anti-HCV in plain areas is higher than islands. Middle-aged and elderly people are the age group with high prevalence, and the anti-HCV positive rate in people under 20 years old is exceptionally low. Gender differences in anti-HCV positive rate have little effect.

[Assessment of sleep-disordered breathing using hypoxia index].

Objective: To analyze the clinical significance of hypoxia index (HI) in assessing the severity of hypoxemia in obstructive sleep apnoea hypopnea syndrome(OSAHS). Methods: A total of 127 patients with a complaint of snoring visiting our hospital were recruited from February 2014 to January 2016. All patients received polysomnography (PSG) test. The PSG results were analyzed by a technician and the SpO(2) data were analyzed by a pre-designed computer software. The patients were grouped according to apnea hypopnea index (AHI) and lowest oxygen saturation (LSpO(2)) respectively. Receiver operating characteristic (ROC) curve was used to evaluate the best HI diagnostic value. Results: The HI (median) of the simple snoring, mild, moderate and severe OSAHS groups (according to AHI) were 0.027(0.004, 0.554), 0.281(0.045, 0.353), 0.429(0.099, 1.677), 21.714(2.737, 95.473), respectively. There were statistically significant correlation between HI and AHI, LSpO(2), ≥3% oxygen desaturation index(ODI(3)), the correlation coefficient being 0.78, -0.92, 0.87(U value were 8.76, -10.34, 9.72, all P<0.01). Grouped according to LSpO(2), the HI was significantly different between groups (H value were 7.62-14.39, all P<0.05). Conclusion: If the HI diagnostic value was set reasonably, it might be used as an effective index for evaluating the severity of OSAHS.

A gyro-stabilized platform leveling loop for marine gravimeter.

An ultra-low-frequency platform leveling loop based on a mixed sensitivity H∞ approach, which considers both the system bandwidth and response speed, was designed and applied to a prototype, two-axis gyro-stabilized platform marine gravimeter CHZ-II. The instrument was developed for regional surveys in deep ocean areas where high-resolution gravity measurements with accuracy 1 mGal are required. Horizontal accelerations in the surge and sway directions are suppressed about 60 dB in the frequency range 0.05 to 0.5 Hz. This typically improves the quality of the gravity data before any processing corrections. The time required for stabilizing the platform at the beginning of a survey line or course change is about 3 min, which improves the data collection efficiency. In May 2015, the first test was conducted in open sea conditions aboard the Chinese State Oceanic Administration's R/V Xiangyanghong 10. Sixteen traverses were run in the South China Sea to evaluate the loop performance. Platform motion tracks and gravity data from the survey were of satisfactory quality. According to analyses of 16 sets of calculated errors, the root mean square repeatability of the pitch and roll off-level angles were less than 10 and 20 arc sec, respectively, with a horizontal acceleration of about 50 Gal. Errors derived from the inability of the platform to maintain perfect sensor leveling during the survey cruise were less than 0.3 mGal.

[A study on effects of immediate bone grafting at mandibular first molar fresh extraction socket on maintaining alveolar bone height after space closure].

Objective: To investigate the effect of immediate bone grafting at mandibular first molar extraction socket on maintaining alveolar bone height after space closure. Methods: Thirty adult orthodontic patients who need to extract mandibular first molar, totally 38 target teeth, were included. The samples were divided into two groups randomly: graft group and non-graft group. All extraction space was closed orthodontically. Dental models of all patients were taken before extraction (T0), before space closure(T1) and after space closure (T2). The distance, time of the space closure and the velocity of tooth movement were recorded. Probing depth (PD) and clinical attachment level (CAL) at six sites (mesial buccal, buccal, mesial lingual, lingual, distal buccal and distal lingual) on adjacent teeth were measured before extraction (T0) and after space closure (T2). Cone-beam CT (CBCT) was taken at T0 and T2 to compare the changes of alveolar bone height at six sites on adjacent teeth using Invivo Dental 5.0 software. Results: The extraction space in both graft group and non-graft group was closed successfully. However, the space in graft group was closed more slowly than in non-graft group. In graft group, PD and CAL at the six sites on both the second molar and the second premolar did not change significantly after space closure, and CBCT showed that the alveolar bone height of the second premolar had no significant difference after treatment. In non-graft group, alveolar bone height decreased in both adjacent teeth and periodontal attachment loss was found after space closure. On average, alveolar bone height and periodontal attachment of the second premolar decreased (0.75±0.16) mm and (0.64±0.15) mm, respectively. Meanwhile, alveolar bone height and periodontal attachment of the second molar decreased (0.79±0.23) mm and (0.80±0.24) mm, respectively. Conclusions: Bone graft immediately after mandibular first molar extraction could delay alveolar bone resorption and preserve the periodontal attachment of the adjacent teeth during space closure. However, the procedure could slow down tooth movement.