Perceptions towards online learning among medical students during the COVID-19 pandemic.

Social distancing has been essential during the COVID-19 pandemic to slow the spread of the disease. Online learning ensures students can participate in learning activities while also maintaining a physical distance from other students. Although online learning was used to prevent the spread of COVID-19, the development of online learning has also been promoted. Here, we sought to explore the perceptions and responses of students to online learning during the pandemic using a cross-sectional study. Electronic questionnaire was used for data collection. Statistical analyses were performed for 1614 valid questionnaires and P < 0.05 was considered statistically significant. Overall, COVID-19 had more effect on female students, such as fear of COVID-19 (2.4 times higher than the number of male students) and length of time spent learning (H = 42.449, P < 0.05). However, the higher the students' grades were, the less the impact of COVID-19. For the style of lessons, all students would prefer shorter lessons (P < 0.05). Female and fifth-grade students were more prefer combined online and face-to-face learning, and male and freshmen students were more likely to prefer face-to-face learning after the pandemic. More than 50% of students thought the main advantage of online learning was convenience, with low efficiency being a disadvantage. The main factors negatively influencing online learning were eyestrain, poor network connections, and poor learning environments at home. In conclusion, synchronous online and face-to-face learning may become more common in future curricula, however the efficiency of online learning and the female students more attentions.

Structural Genomic Analysis of SARS-CoV-2 and Other Coronaviruses.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative agent of the coronavirus disease 2019 (COVID-19) pandemic. In this study, we conducted a comparative analysis of the structural genes of SARS-CoV-2 and other CoVs. We found that the sequence of the E gene was the most evolutionarily conserved across 200 SARS-CoV-2 isolates. The E gene and M gene sequences of SARS-CoV-2 and NC014470 CoV were closely related and fell within the same branch of a phylogenetic tree. The absolute diversity of E gene and M gene sequences of SARS-CoV-2 isolates was similar to that of common CoVs (C-CoVs) infecting other organisms. The absolute diversity of the M gene sequence of the KJ481931 CoV that can infect humans was similar to that of SARS-CoV-2 and C-CoVs infecting other organisms. The M gene sequence of KJ481931 CoV (infecting humans), SARS-CoV-2 and NC014470 CoV (infecting other organisms) were closely related, falling within the same branch of a phylogenetic tree. Patterns of variation and evolutionary characteristics of the N gene and S gene were very similar. These data may be of value for understanding the origins and intermediate hosts of SARS-CoV-2.

Isobaric Tags for Relative and Absolute Quantitation in Proteomic Analysis of Potential Biomarkers in Invasive Cancer, Ductal Carcinoma In Situ, and Mammary Fibroadenoma.

OBJECTIVES: Breast malignancy is a serious threat to women's health around the world. Following the rapid progress in the field of cancer diagnostics and identification of pathological markers, breast tumor treatment methods have been greatly improved. However, for invasive, ductal carcinomas and mammary fibroadenoma, there is an urgent demand for better breast tumor-linked biomarkers. The current study was designed to identify diagnostic and/or therapeutic protein biomarkers for breast tumors. METHODS: A total of 140 individuals were included, comprising 35 healthy women, 35 invasive breast cancers (IBC), 35 breast ductal carcinomas in situ (DCIS), and 35 breast fibroadenoma patients. Isobaric tags for relative and absolute quantitation (iTRAQ) proteomic analysis was employed to characterize differentially expressed proteins for potential biomarkers in IBC, DCIS, and fibroadenomas by comparisons with their matched adjacent tissues and/or normal breast tissues. The public databases Metascape and String were used for bioinformatic analyses. RESULTS: Using the proteomics approach, we identified differentially expressed proteins in tissues of different breast tumors compared to normal/adjacent breast tissues, including 100 in IBC, 52 in DCIS, and 44 in fibroadenoma. Among the 100 IBC differentially expressed proteins, 37 were found to be specific to this type of cancer only. Additionally, four proteins were specifically expressed in DCIS and four in fibroadenoma. Compared to corresponding adjacent tissues and normal breast tissues, 18 step-changing proteins were differentially expressed in IBC, 14 in DCIS, and 13 in fibroadenoma, respectively. Compared to DCIS and normal breast tissues, 65 proteins were differentially expressed in IBC with growing levels of malignancy. CONCLUSIONS: The identified potential protein biomarkers may be used as diagnostic and/or therapeutic targets in breast tumors.

Comparative analysis of SARS-CoV-2 and its receptor ACE2 with evolutionarily related coronaviruses.

The pandemic COVID-19 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and it is spreading very rapidly worldwide. To date, the origin and intermediate hosts of SARS-CoV-2 remain unclear. In this study, we conducted comparative analysis among SARS-CoV-2 and non-SARS-CoV-2 coronavirus strains to elucidate their phylogenetic relationships. We found: 1, the SARS-CoV-2 strains analyzed could be divided into 3 clades with regional aggregation; 2, the non-SARS-CoV-2 common coronaviruses that infect humans or other organisms to cause respiratory syndrome and epizootic catarrhal gastroenteritis could also be divided into 3 clades; 3, the hosts of the common coronaviruses closest to SARS-CoV-2 were Apodemus chevrieri (a rodent), Delphinapterus leucas (beluga whale), Hypsugo savii (bat) , Camelus bactrianus (camel) and Mustela vison (mink); and 4, the gene sequences of the receptor ACE2 from different hosts could also be divided into 3 clades. The ACE2 gene sequences closest to that of humans in evolution include those from Nannospalax galili (Upper Galilee mountains blind mole rat), Phyllostomus discolor (pale spear-nosed bat), Mus musculus (house mouse), Delphinapterus leucas (beluga whale), and Catharus ustulatus (Swainson's thrush). We conclude that SARS-CoV-2 may have evolved from a distant common ancestor with the common coronaviruses but not a branch of any of them, implying that the prevalent pandemic COVID-19 agent SARS-CoV-2 may have existed in a yet to be identified primary host for a long time.

Associations of CXCL1 gene 5'UTR variations with ovarian cancer.

BACKGROUND: There are about 2.4 hundred thousand new cases and 1.5 hundred thousand deaths of ovarian cancer (OC) annually in the world. Chronic inflammation is a risk factor for OC. C-X-C motif chemokine ligand 1 (CXCL1) defects may facilitate inflammation and transactivate EGFR in ovarian cancer, but the precise haplotypes associated with the potential diseases remained largely unknown. In this work, we characterized CXCL1 gene variations to elucidate their possible associations with OC. METHODS: We analyzed the CXCL1 gene for 300 OC patients with 400 healthy participants as controls. The statistical analyses and Hardy-Weinberg equilibrium tests of the patients and control populations were conducted using the SPSS software (version 19.0) and Plink (version 1.9). RESULTS: The variants rs11547681, rs201090116, rs199791199, rs181868085, rs4074 and rs1814092 within or near the CXCL1 gene were characterized. The genetic heterozygosity of rs11547681 and rs4074 was very high. Statistical analysis showed that the variant rs11547681 in the gene was closely associated with the risk of OC in the Chinese Han population, although this variant was not associated with FIGO stages or pathological grades of the patients. CONCLUSIONS: Rs11547681 in CXCL1 gene was associated with the risk of OC in the Chinese Han population.

Identification of epigenetic factor KAT2B gene variants for possible roles in congenital heart diseases.

Congenital heart disease (CHD) is a group of anatomic malformations in the heart with high morbidity and mortality. The mammalian heart is a complex organ, the formation and development of which are strictly regulated and controlled by gene regulatory networks of many signaling pathways such as TGF-ß. KAT2B is an important histone acetyltransferase epigenetic factor in the TGF-ß signaling pathway, and alteration in the gene is associated with the etiology of cardiovascular diseases. The aim of this work was to validate whether KAT2B variations might be associated with CHD. We sequenced the KAT2B gene for 400 Chinese Han CHD patients and evaluated SNPs rs3021408 and rs17006625. The statistical analyses and Hardy-Weinberg equilibrium tests of the CHD and control populations were conducted by the software SPSS (version 19.0) and PLINK. The experiment-wide significance threshold matrix of LD correlation for the markers and haplotype diagram of LD structure were calculated using the online software SNPSpD and Haploview software. We analyzed the heterozygous variants within the CDS region of the KAT2B genes and found that rs3021408 and rs17006625 were associated with the risk of CHD.

RBPJ polymorphisms associated with cerebral infarction diseases in Chinese Han population: A Clinical Trial/Experimental Study (CONSORT Compliant).

TRIAL DESIGN: Cerebral small vessel diseases (CSVDs) are a group of brain pathological processes involving cerebral small arteries, brain venules, and capillaries. The recombination signal-binding protein Jκ (RBPJ) is implicated in the pathogenesis of these diseases but its actual roles need confirmation. The aim of this work was to evaluate variations in RBPJ gene for their possible associations with the disease. METHODS: The RBPJ gene was sequenced for 400 patients with cerebral infarction disease and 600 normal controls. The statistical analyses and Hardy-Weinberg equilibrium tests of the patients and control populations were conducted using the SPSS software (version 19.0) and Plink (version 1.9), Haploview software, and online software SNPSpD. RESULTS: We characterized variants rs2871198, rs1397731, rs3822223, rs2077777, rs2270226, and rs2788861 within or near the RBPJ gene. The genetic heterozygosity of rs2871198, rs1397731, rs3822223, rs2077777, and rs2270226 was very high. Statistical analysis showed that the variants rs2270226 and rs2077777 in the gene were associated with the risk of cerebral infarction diseases in the Chinese Han population. CONCLUSIONS: rs2270226 and rs2077777 in the RBPJ gene were associated with the risk of cerebral infarction diseases in the Chinese Han population.

Rs2459976 in ZW10 gene associated with congenital heart diseases in Chinese Han population.

Congenital heart diseases (CHD) are a large group of prevalent and complex anatomic malformations of the heart, with the genetic basis remaining largely unknown. Since genes or factors associated with the differentiation of human embryonic stem (HES) cells would affect the development of all embryonic tissues, including cardiac progenitor cells, we postulated their potential roles in CHD. In this study, we focused on ZW10, a kinetochore protein involved in the process of proper chromosome segregation, and conducted comparative studies between CHD patients and normal controls matched in gender and age in Chinese Han populations. We identified three variations in the ZW10 gene, including rs2885987, rs2271261 and rs2459976, which all had high genetic heterozygosity. Association analysis of these genetic variations with CHD showed correlation between rs2459976 and the risk of CHD. We conclude that rs2459976 in the ZW10 gene is associated with CHD in Chinese Han populations.

Different effection of p.1125Val>Ala and rs11954856 in APC on Wnt signaling pathway.

Colorectal cancer (CRC) is among the most common and fatal forms of solid tumors worldwide and more than two thirds of CRC and adenomas patients have APC gene mutations. APC is a key regulator in the Wnt/ß-catenin signaling pathway but its roles in CRC remains to be elucidated. In this study, we compared APC genes between CRC patients and controls to determine possible associations of nucleotide changes in the APC gene with the pathways involved in CRC pathogenesis. All participants received physical and enteroscopic examinations. The APC gene was sequenced for 300 Chinese Han CRC patients and 411 normal controls, and the expression levels of genes in the signaling pathway were analyzed using Western Blotting. Statistical analyses were conducted using SPSS (version 19.0) software. We found that rs11954856 in the APC gene was associated with colorectal cancer and could increase the expression levels of APC, ß-catenin, TCF7L1, TCF7L2 and LEF1 genes in the pathway in the CRC patients, demonstrating the involvement of APC in the pathological processes leading to CRC.

[Expectant therapy versus curettage for retained products of conception after second trimester termination of pregnancy: analysis of outcomes and complications].

OBJECTIVE: To evaluate the prognosis and complications of expectant therapy and curettage for retained product of conception (RPOC) after second trimester termination of pregnancy (TOP). METHODS: A total of 270 patients with RPOC following second trimester TOP in Nanfang Hospital between January, 2014 and December, 2015 were included in this study. The duration of vaginal bleeding time and menstruation recovery interval were compared between patients receiving expectant therapy and curettage for RPOC, and binary logistic regression was used to assess the risk factors for complications in bivariate and multivariate analyses. RESULTS: The duration of vaginal bleeding time was significantly longer in expectant therapy group than in curettage group (P=0.005), while the menstruation recovery interval did not differ significantly between the two groups. The incidence of vaginal bleeding time for over 42 days was significantly higher in curettage group than in expectant therapy group (P=0.040), and the incidence of a menstruation recovery interval beyond 60 days was comparable between them. The incidence of complications was significantly higher in curettage group than in expectant therapy group either with adjustment of age, gravidity, parity, history of uterine surgery status, gestational age, type of indications, regimens for TOP and induction-abortion interval (OR=18.26 [95% CI: 3.57-93.42], P<0.001) or without adjustment (OR=10.60, [95% CI: 2.36-47.66], P=0.002). CONCLUSION: Expectant therapy and curettage for RPOC after second trimester TOP have comparable prognosis, but curettage is associated with a significantly higher rate of complications.

Characterization of soluble N-ethylmaleimide-sensitive factor attachment protein receptor gene STX18 variations for possible roles in congenital heart diseases.

Congenital heart disease (CHD) is among the most prevalent and complex congenital anatomic malformations in newborns. Interactions of cardiac progenitor with a broad range of cellular regulatory factors play key roles in the formation of mammalian heart and pathogenesis of CHD. STX18 is a soluble N-ethylmaleimide-sensitive factor attachment protein receptor, which is involved in numeral cellular activities such as organelle assembly and the cell cycle. The aim of this work was to find evidence on whether STX18 variations might be associated with CHD in Chinese Han populations. We evaluated SNPs rs2044, rs33952588, rs61740788, rs12504020 and rs12644497, which are located within the exon or intron sequences of the STX18 gene, for 310 Chinese Han CHD patients and 400 non-CHD controls. Using SPSS software (version 19.0) and the online software OEGE, we conducted statistical analyses and Hardy-Weinberg equilibrium test, respectively. Among the five SNPs identified in the STX18 gene, rs33952588 and rs61740788 had very low genetic heterozygosity. In contrast, the genetic heterozygosity of the remaining three variations rs12504020 and rs12644497 near the 5'UTR and rs2044 within 3'UTR of the STX18 gene was considerably high. Analysis of associations of these genetic variations with the risk of CHD showed that rs12644497 (P value=0.017<0.05) was associated with the risk of CHD, specifically VSD and ASD, whereas rs12504020 (P value=0.560>0.05) and rs2044 (P value=0.972>0.05) were not. The SNP rs12644497 in the STX18 gene was associated with CHD in Chinese Han populations.

Characterization of variations in IL23A and IL23R genes: possible roles in multiple sclerosis and other neuroinflammatory demyelinating diseases.

Multiple sclerosis is among the most serious inflammatory demyelinating diseases (IDD). Interleukin-23A (IL23A) regulates and coordinates the activities of immune cells by interacting with its receptor IL23R and plays key roles in the pathogenesis of immune inflammatory diseases. IDD, deemed to be a kind of autoimmune diseases, may involve IL23A in the pathogenesis. The aim of this work was to validate the hypothesized involvement of IL-23A and its receptor in IDD. We sequenced the IL-23A and IL-23R genes for 206 Chinese Han IDD patients and evaluated SNPs within or near those genes. The serum levels of IL23A in IDD participants were analyzed using ELISA. The statistical analyses were conducted using Chi-Square Tests as implemented in SPSS (version 19.0). The Hardy-Weinberg equilibrium test of the population was carried out using online software OEGE. Three variants rs2066808, rs2371494, rs11575248 in IL-23A gene and one variant rs1884444 in IL-23R gene were demonstrated to be associated with the risk of MS or other IDD diseases, and the expression level of serum IL-23A in the MS patients was also altered. We conclude that variants in IL-23A and IL-23R genes were associated with the risk of MS or other IDD diseases.

Combined effects of age and polymorphisms in Notch3 in the pathogenesis of cerebral infarction disease.

Cerebral infarction disease is a severe hypoxic ischemic tissue necrosis in the brain, often leading to long-term functional disability and residual impairments. The Notch signaling pathway plays key roles in proliferation and survival of the stem/progenitor cells of the central and peripheral nervous systems. Notch3 is an important member of the pathway, but the relationships between the genetic abnormalities and cerebral infarction disease still remain unclear. The aim of this work was to evaluate variations in Notch3 gene for their possible associations with the cerebral infarction disease. We sequenced the Notch3 gene for 260 patients with cerebral infarction disease, 300 normal controls with old ages and 300 normal controls with younger ages, and identified the variations. The statistical analyses were conducted using Chi-Square Tests as implemented in SPSS (version 19.0). The Hardy-Weinberg equilibrium test of the population was carried out using the online software OEGE. Six variations, including rs1044116, rs1044009, rs1044006, rs10408676, rs1043996 and rs16980398 within or near the Notch3 gene, were found. The genetic heterozygosity of rs1044116, rs1044009, rs1044006, and rs1043996 was very high, whereas that of rs10408676 and rs16980398 was very low. Statistical analyses showed that rs1044009 and rs1044006 were associated with the risk of cerebral infarction disease in the Chinese Han agedness population. The SNPs rs1044009 and rs1044006 in the Notch3 gene were associated with the risk of cerebral infarction diseases in the Chinese Han agedness population.

Characterization of human bone morphogenetic protein gene variants for possible roles in congenital heart disease.

Congenital heart disease (CHD) is a complex illness with high rates of morbidity and mortality. In embryonic development, the heart is the first formed organ, which is strictly controlled by gene regulatory networks, including transcription factors, signaling pathways, epigenetic factors and microRNAs. Bone morphogenetic protein (BMP)-2 and -4 are essential in cardiogenesis as they can induce the expression of transcription factors, NKX2­5 and GATA binding protein 4, which are important in the development of the heart. The inhibition of BMP­2 and ­4 inhibits the late expression of NKX2-5 and affects cardiac differentiation. The aim of the present study was to investigate whether BMP-2 and ­4 variations may be associated with CHD in Chinese Han populations. The rs1049007, rs235768 and rs17563 single nucleotide polymorphisms (SNPs), which are genetic variations located within the translated region of the BMP-2 and -4, were evaluated in 230 patients with CHD from the Chinese Han population and 160 non-CHD control individuals. Statistical analyses were performed using the χ2 test, implemented using SPSS software (version 13.0). The Hardy-Weinberg equilibrium test was performed on the population using online Online Encyclopedia for Genetic Epidemiology studies software, and multiple-sequence alignments of the BMP proteins were performed using Vector NTI software. No statistically significant associations were identified between these genetic variations and the risk of CHD (rs1049007, P­value=0.560; rs235768, P­value=0.972; rs17563, P­value=0.787). In addition, no correlation was found between the patients with CHD and the non­CHD control individuals. Therefore, the rs1049007, rs235768 and rs17563 genetic variations of BMP-2 were not associated with CHD in the Chinese Han population.

Polymorphisms in the CHIT1 gene: Associations with colorectal cancer.

Colorectal cancer (CRC) is one of the most common solid tumors worldwide, often associated with inflammation. The microbes in the human intestine have a key role in inflammations and CRC. Chitotriose renders growth advantage to some bacteria, especially some pathogens, and thus has a role in inflammations. The enzyme chitotriosidase, encoded by the CHIT1 gene of the host, may degrade chitotriose with different efficiencies depending on the alleles. We sequenced the CHIT1 gene for 320 Chinese Han CRC patients and 404 normal controls, and focused on variations rs61745299 and rs35920428 within the CHIT1 gene for their possible roles in CRC. Statistical analyses were conducted using Chi-Square Tests as implemented in SPSS (version 19.0). Multiple sequence alignment was conducted using the Vector NTI, and protein expression levels were analyzed by western blotting. The two variations, rs61745299 and rs35920428 within the CDS region of CHIT1 gene, were associated with the risk of CRC (both with P values < 0.001). Western blotting analysis showed that the variations increased the expression levels of the CHIT1 and C-reaction protein genes in the cancer tissue. We conclude that the two variations of CHIT1, rs61745299 and rs35920428, increase expression of the gene and are associated with CRC in Chinese Han populations.

Characterization of Transcriptional Repressor Gene MSX1 Variations for Possible Associations with Congenital Heart Diseases.

BACKGROUND: The human heart consists of several cell types with distinct lineage origins. Interactions between these cardiac progenitors are very important for heart formation. The muscle segment homeobox gene family plays a key role in the cell morphogenesis and growth, controlled cellular proliferation, differentiation, and apoptosis, but the relationships between the genetic abnormalities and CHD phenotypes still remain largely unknown. The aim of this work was to evaluate variations in MSX1 and MSX2 for their possible associations with CHD. METHODS: We sequenced the MSX1 and MSX2 genes for 300 Chinese Han CHD patients and 400 normal controls and identified the variations. The statistical analyses were conducted using Chi-Square Tests as implemented in SPSS (version 19.0). The Hardy-Weinberg equilibrium test of the population was carried out using the online software OEGE. RESULTS: Six variations rs4647952, rs2048152, rs4242182, rs61739543, rs111542301 and rs3087539 were identified in the MSX2 gene, but the genetic heterozygosity of those SNPs was very low. In contrast, the genetic heterozygosity of two variations rs3821949 near the 5'UTR and rs12532 within 3'UTR of the MSX1 gene was considerably high. Statistical analyses showed that rs3821949 and rs12532 were associated with the risk of CHD (specifically VSD). CONCLUSIONS: The SNPs rs3821949 and rs12532 in the MSX1 gene were associated with CHD in Chinese Han populations.

Transcriptional Factor Snail Mediates Epithelial-Mesenchymal Transition in Human Bronchial Epithelial Cells Induced by Silica.

Epithelial-mesenchymal transition (EMT) plays an important role in fibrotic diseases. We have previously showed that silica induces EMT in human bronchial epithelial cells (BECs); however, the underlying mechanism of silica-induced EMT is poorly understood. In the present study, we investigated the role of Snail in silica-induced EMT in human BECs in vitro. Human BECs were treated with silica at various concentrations and incubation times. Then MTT assay, western blot, electrophoretic mobility shift assay (EMSA), and small interfering RNA (siRNA) transfection were performed. We found that silica increased the expression and DNA binding activity of Snail in human BECs. SNAI siRNA inhibited the silica-induced expression of Snail. Moreover, SNAI siRNA upregulated the expression of epithelial marker E-cadherin, but attenuated the expression of mesenchymal marker α-smooth muscle actin and vimentin in silica-stimulated cells. These results suggest that Snail mediates the silica-induced EMT in human BECs.

Identification of two novel critical mutations in PCNT gene resulting in microcephalic osteodysplastic primordial dwarfism type II associated with multiple intracranial aneurysms.

Microcephalic osteodysplastic primordial dwarfism type II (MOPD II) is a highly detrimental human autosomal inherited recessive disorder. The hallmark characteristics of this disease are intrauterine and postnatal growth restrictions, with some patients also having cerebrovascular problems such as cerebral aneurysms. The genomic basis behind most clinical features of MOPD II remains largely unclear. The aim of this work was to identify the genetic defects in a Chinese family with MOPD II associated with multiple intracranial aneurysms. The patient had typical MOPD II syndrome, with subarachnoid hemorrhage and multiple intracranial aneurysms. We identified three novel mutations in the PCNT gene, including one single base alteration (9842A>C in exon 45) and two deletions (Del-C in exon 30 and Del-16 in exon 41). The deletions were co-segregated with the affected individual in the family and were not present in the control population. Computer modeling demonstrated that the deletions may cause drastic changes on the secondary and tertiary structures, affecting the hydrophilicity and hydrophobicity of the mutant proteins. In conclusion, we identified two novel mutations in the PCNT gene associated with MOPD II and intracranial aneurysms, and the mutations were expected to alter the stability and functioning of the protein by computer modeling.

Identification of a novel mutation associated with familial adenomatous polyposis and colorectal cancer.

Colorectal cancer (CRC) is among the most fatal forms of solid tumor in men and women. While the majority of diagnosed CRC cases are sporadic, 15­25% of patients have a family history of adenomatous polyposis and CRC; however, the associated gene mutations remain largely unidentified. The aim of the present study was to investigate the genomes of a four­generational Chinese Han family with familial adenomatous polyposis and CRC to identify the potential genetic anomalies associated with the disease. Diagnoses were made by physical and enteroscopic examinations of all the family members. Mutational analyses of the potential CRC­associated genes were carried out by direct gene sequencing, and the statistically significant differences in polymorphisms between normal and diseased populations were determined. Multiple sequence alignment and protein modeling were conducted using the Vector NTI and DNAMAN software tools. Clinical and pathological features of all the examined patients were consistent with typical familial adenomatous polyposis (FAP) syndrome. From the genomes of these family members, a 131564T>C (p.1125Val>Ala) mutation was identified in exon 15 of the APC gene, and a 1126G>C (p.324Gln>His) mutation was identified in exon 12 of the MUTYH gene. The 131564T>C mutation co­segregated with the affected individuals in the family and was specifically associated with the incidence of CRC (P=0.018<0.05). The 1125Val residue was highly conserved in the APC protein, and the p.1125Val>Ala mutation led to changes in the secondary structure and hydrophilicity of the APC protein. In conclusion, the APC gene mutation 131564T>C is associated with FAP and the pathogenesis of CRC.

Characterization of SMAD3 Gene Variants for Possible Roles in Ventricular Septal Defects and Other Congenital Heart Diseases.

BACKGROUND: Nodal/TGF signaling pathway has an important effect at early stages of differentiation of human embryonic stem cells in directing them to develop into different embryonic lineages. SMAD3 is a key intracellular messenger regulating factor in the Nodal/TGF signaling pathway, playing important roles in embryonic and, particularly, cardiovascular system development. The aim of this work was to find evidence on whether SMAD3 variations might be associated with ventricular septal defects (VSD) or other congenital heart diseases (CHD). METHODS: We sequenced the SMAD3 gene for 372 Chinese Han CHD patients including 176 VSD patients and evaluated SNP rs2289263, which is located before the 5'UTR sequence of the gene. The statistical analyses were conducted using Chi-Square Tests as implemented in SPSS (version 13.0). The Hardy-Weinberg equilibrium test of the population was carried out using the online software OEGE. RESULTS: Three heterozygous variants in SMAD3 gene, rs2289263, rs35874463 and rs17228212, were identified. Statistical analyses showed that the rs2289263 variant located before the 5'UTR sequence of SMAD3 gene was associated with the risk of VSD (P value=0.013 <0.05). CONCLUSIONS: The SNP rs2289263 in the SMAD3 gene is associated with VSD in Chinese Han populations.