Peipei Liu

Impact of endothelial nitric oxide synthase gene polymorphism on severity of enterovirus 71-infection in Chinese children

OBJECTIVES Genetic polymorphism G894T on the endothelial nitric oxide synthase (eNOS) gene has been reported as a susceptibility factor in a number of diseases, but evidence of its effect on enterovirus 71 (EV71) infection is lacking. This study investigated the possible association between this polymorphism (rs1799983) and disease severity in Chinese children with EV71 infection. DESIGN AND METHODS 185 children with EV71 infection (83 with severe and 102 with mild disease) and 234 control healthy children underwent testing with polymerase chain reaction-restriction fragment length polymorphism (PCR-RLFP) to detect G894T polymorphism. In addition, plasma levels of nitric oxide (NO), interleukin 1 beta (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor-alpha (TNF-α) and serum eNOS activity were measured according to genotype. RESULTS The presence of GT+TT genotypes and T allele were associated with severe cases compared to genotype GG (OR 2.5, 95% CI 1.2-5.3, P=0.017) and G (OR 2.4, 95% CI 1.2-4.8, P=0.011). Furthermore, in EV71 encephalitis, GT+TT genotype and T allele were also more frequent than GG and G (P<0.05). The NO level and eNOS activity in T carriers (GT+TT) (84.3±2.5μmol/L and 14.4±1.8U/mL) were significantly less compared to in G carriers (GG) (92.0±1.5μmol/L and 19.1±1.7U/mL, P<0.001). But T carriers had higher plasma levels of IL-1β, IL-6, and TNF-α than people without a T allele (P<0.001), and a significant negative correlation was observed between NO and cytokine levels. CONCLUSION The results indicate that carrying the T allele of the eNOS G894T gene polymorphism was associated with EV71 infection, and could be a susceptibility factor in the development of EV71 infection in Chinese children.

Association of CPT II Gene With Risk of Acute Encephalitis in Chinese Children

Background: Mutations of the CPT II gene cause CPT II deficiency, an inborn metabolic error affecting mitochondrial fatty acid &bgr;-oxidation. Associations and mechanisms of CPT II gene with acute encephalitis need to be elucidated. We aimed to investigate the associations of CPT II gene variants and CPT II activity with development of acute encephalitis. Methods: A total of 440 blood-unrelated Chinese children with acute encephalitis and 229 healthy controls were enrolled in this case control study. Sequencing of 5 exons of the CPT II gene was carried out to look for the variants associated with acute encephalitis. CPT II activity and blood adenosine triphosphate concentration were examined during high fever and convalescent phase to confirm the hypothesis. Results: Polymorphism of rs2229291 in CPT II gene was significantly associated with an increased risk of acute encephalitis (P = 0.031), where as rs1799821 displayed a decrease risk (P = 0.018). Positive association was found between rs2229291 and patients with fever at onset of seizure and degree of pathogenetic condition (P = 0.018 and P = 0.023), but not for rs1799821. CPT II activity of patients with rs2229291 reduced greatly during high fever compared with the convalescent phase. Conclusions: rs2229291 and rs1799821 variants in CPT II gene might be 1 of the predisposing factors of acute encephalitis.

Association of the OAS3 rs1859330 G/A genetic polymorphism with severity of enterovirus-71 infection in Chinese Han children

The 2’5’-oligoadenylate synthetase (OAS) is an interferon (IFN)-induced protein that plays an important role in the antiviral action of IFN, with OAS3 being one of the four OAS classes (OAS1, OAS2, OAS3, OASL). The effect of OAS on several infectious viral diseases has been reported; however, a study of the effect of OAS3 on enterovirus 71 (EV71) is lacking. The purpose of this study was to evaluate the association of the OAS3 rs1859330 G/A genetic polymorphism with susceptibility and severity of EV71 infection. We investigated 370 Chinese Han children with hand-foot-mouth disease (HFMD) (214 of which were mild cases while 156 were severe). An improved multiplex ligation detection reaction (iMLDR) technique was carried out to examine the genotype. The AA genotype distribution (p = 0.002) and A allele frequency (OR = 1.83, 95% CI 1.32-2.52, p < 0.001) of OAS3 rs1859330 in severe cases were significantly higher than in mild cases. When comparing the different genotypes in EV71-infected patients, there were statistical differences in relation to rash (p = 0.03), oral ulcers (p = 0.005), pathologic reflex (p = 0.003), WBC counts (p = 0.032), CRP (p = 0.024), BG concentrations (p = 0.029), ALT (p = 0.02), and EEG (p = 0.019). However, there were no differences in relation to age, gender, AST, CK–MB, CT/ MRI, as well as some symptoms and signs (e.g. duration of fever (days), headache, convulsions, consciousness disturbance, paralysis, sign of meningeal irritation). In the cerebrospinal fluid (CSF) of severe cases, there were no differences in the levels of white cells, protein, glucose, chloride, lymphocytes and monocytes between the different genotypes. The plasma levels of IFN-γ in EV71-infected patients were significantly higher than in the control group (p < 0.01). IFN-γ concentrations in severe cases were lower in A allele carriers (AA+GA) (118.5 ± 12.6pg/mL) than in GG homozygotes (152.6 ± 56.3pg/mL p < 0.05). These findings suggest that the OAS3 rs1859330 G/A genetic polymorphism is associated with the severity of EV-71 infection, and that the A allele is a risk factor for the development of severe EV71 infection.

Association of Toll-like receptor 3 gene polymorphism with the severity of enterovirus 71 infection in Chinese children

Enterovirus 71 (EV71) infection has become one of the major threats to children globally in recent years. Toll-like receptor 3 (TLR3) plays an essential role in host defense against EV71 infection. This study was designed to assess the possible association between the TLR3c.1377C/T polymorphism and disease severity in Chinese children with EV71 infection. The TLR3c.1377C/T gene polymorphism was identified in EV71-infected patients (n = 177), including mild cases (n = 99) and severe cases (n = 78) as well as healthy controls (n = 225), using improved multiplex ligation detection reaction (iMLDR) technology. Serum levels of IFN-γ and IL-4 were measured using enzyme-linked immunosorbent assays. The presence of the TT genotype (p = 0.030) and the T allele (OR, 1.8; 95% CI, 1.2-2.8; p = 0.010) was significantly more frequent in severe cases. The plasma levels of IFN-γ and the IFN-γ/IL-4 ratio were significantly lower with the TT (102.0 ± 24.2 pg/mL, p < 0.01 and 14.2 ± 2.8, p < 0.001) and CT genotypes (114.1 ± 26.2 pg/mL, p < 0.05 and 18.0 ± 3.1, p < 0.001) than with the CC genotype (135.5 ± 36.8 pg/mL and 24.9 ± 4.7), but the plasma levels of IL-4 with the TT (7.3 ± 1.7 pg/mL, p < 0.01) and CT genotypes (6.4 ± 1.3 pg/mL, p < 0.05) were significantly higher than with the CC genotype (5.5 ±1.3 pg/mL). These findings suggest that the TLR3c.1377T allele is associated with susceptibility to severe EV71 infection in Chinese children.

Oligoadenylate synthetase 3 S381R gene polymorphism is associated with severity of EV71 infection in Chinese children

BACKGROUND Oligoadenylate synthetase 3 (OAS3) is interferon-induced antiviral enzyme, playing a significant role in the innate immune response. Genetic polymorphism in OAS3 gene has been reported to be a susceptibility factor in many infected diseases, but evidence of its effect on enterovirus 71 (EV71) infection is still lacking. OBJECTIVES An attempt study was made to investigate whether genetic polymorphism of OAS3 S381R is associated with the severity of EV71 infection in Chinese children. STUDY DESIGN Retrospectively sumed up the clinical onsets and experimental results for 249 cases with EV71 infection (including 151 mild cases and 98 severe cases) and 243 controls. An improved multiplex ligation detection reaction (iMLDR) technique was carried out to analyze polymorphism in OAS3 S381R G/C gene for genetic association analyses. The plasma levels of IFN-γ were determined by enzyme-linked immunosorbent assays. RESULTS The distribution of OAS3 S381R CC genotype (73.47%) and C allele (85.20%) in severe cases was markedly higher than in mild cases (45.70%, P < .01; 67.88%, P < .01). The blood IFN-γ levels of severe cases were significantly lower in CC genotype (131.66 ± 10.84 pg/mL) compared to GG (183.37 ± 24.50 pg/mL, p < .01) and GC genotype (168.48 ± 26.57 pg/mL, p < .01). CONCLUSIONS Carrying the C allele of the OAS3 S381R gene could be a susceptibility factor in the development of severe EV71 infection in Chinese children.

A case of Pitt-hopkins Syndrome with de novo mutation in TCF4: Clinical features and treatment for epilepsy

Pitt‐Hopkins syndrome (PTHS), belonging to the group of 18q‐syndromes, is a rare genetic disorder caused by mutations in TCF4. PTHS is characterized by distinctive facial appearance, intermittent hyperventilation, intellectual disability and developmental delay. Although patients with PTHS generally have various systemic symptoms, most of them with a TCF4 mutation manifest the central nervous system (CNS) disorders. We described the first Chinese case with Pitt‐Hopkins syndrome based on clinical presentations and genetic findings. In addition to the typical features of PTHS, the girl also had paroxysms of tachypnea followed by cyanosis and recurrent seizures. Comprehensive medical examinations were performed including metabolic screening, hepatic and renal function evaluation, abdominal and cardiac ultrasounds. The presence of epileptic discharges in electroencephalography and abnormal brain magnetic resonance imaging were found. High‐throughput sequencing was used to detect genetic mutations associated with CNS disorders. Sanger sequencing was used to confirm the mutations in the patient. The c.2182C＞T (p.Arg728Ter) mutation was a de novo nonsense mutation at exon 18 in the TCF4 gene of the patient. In conclusion, we have identified a de novo nonsense mutation of TCF4 carried by a Chinese girl with PTHS. The patient underwent anti‐epileptic therapy (sodium valproate, levetiracetam, clonazepam), resulting in a reduction of the seizures.

The biochemical characterization of a missense mutation m.8914C>T in ATP6 gene associated with mitochondrial encephalomyopathy

Mutations in ATP6 gene are frequent causes of mitochondrial encephalomyopathies. ATP6 gene encodes one subunit of complexⅤ. The present study described a missense mutation in ATP6 gene in a 8‐year‐old Chinese boy with mitochondrial encephalomyopathy. We identified one missense mutation in ATP6 gene (m.8914C>T) by mitochondrial DNA sequencing. This mutation altered the amino acid proline in serine, and alterative protein is predicted to be harmful. The mutation load in blood sample of patient is 59.49%. Activity of all mitochondrial complexes in blood are normal, however, the total function of mitochondrial oxidative phosphorylation were declined (including pathwayⅠ, pathwayⅡ and pathwayⅣ). The missense mutation (m.8914C>T) in ATP6 gene could result in abnormal function of complexV and is related with mitochondrial encephalomyopathy.

Gene analysis: A rare gene disease of intellectual deficiency-Cohen syndrome

Cohen syndrome is a rare, genetic, connective‐tissue disorder, which is caused by mutations in the gene COH1 (VPS13B, Vacuolar Protein Sorting 13 Homolog B) at the chromosome 8q22. The disease is rare reported, which major clinical features include postnatal microcephaly, obesity, short stature, intellectual disability, progressive retinal dystrophy, intermittent neutropenia and many other unusual facial feature. We report four patients in China who were diagnosed with Cohen syndrome by genetic testing and clinical manifestations. At the same time, we review the related literature, and further expound the molecular mechanism of the disease, a variety of clinical manifestations, treatment and prognosis.

Polymorphism of OAS2 rs739901 C/A Involves the Susceptibility to EV71 Infection in Chinese Children

SummaryThis study aimed to assess the relationship of OAS2 rs739901 5,-flanking C/A polymorphisms with the susceptibility to Enterovirus-71 (EV71) infection. We investigated 294 hand-foot-mouth disease (HFMD) Chinese children with EV71 infection (165 mild cases and 129 encephalitis cases). The improved multiplex ligation detection reaction (iMLDR) technique was used to test the genotypes. In EV71-infected patients, the CA genotype distribution (P=0.007), A allele frequency (OR 1.32,95% CI 1.0–1.7, P=0.034) and CA+AA carriage frequency (P=0.003) of OAS2 rs739901 5′-flanking were obviously elevated as compared with controls, but there were no statistically significant differences between mild cases and encephalitis cases. In EV71-infected patients, the counts of white blood cells (P=0.034) and blood glucose concentrations (P=0.042) were raised in A carriers (CA+AA). Among different genotypes of encephalitis cases, the contents of cerebrospinal fluid (CSF) showed no significant differences. IFN-γ levels in EV71-infected patients were higher than those in controls (mild group vs. control group, P<0.01; encephalitis group vs. control group, P<0.01;). In encephalitis cases, IFN-γ levels were reduced (P<0.05) in A carriers compared to CC genotype, however, there were no significant differences between genotypes CA and AA (P=0.226). These findings suggest that OAS2 rs739901 5′-flanking C/A genetic polymorphisms involve the susceptibility to EV71 infection, and A allele might be a risk factor of the susceptibility to EV-71 infection.

Chinese cases of early infantile epileptic encephalopathy: a novel mutation in the PCDH19 gene was proved in a mosaic male- case report

BackgroundThe link between the protocadherin-19 (PCDH19) gene and epilepsy suggests that an unusual form of X-linked inheritance affects females but is transmitted through asymptomatic males. Individuals with epilepsy associated with mutations in the PCDH19 gene display generalized or focal seizures with or without fever sensitivity. The clinical manifestation of the condition ranges from mild to severe, resulting in intellectual disability and behavioural disturbance. In the present study, we assessed mutations in the PCDH19 gene and the clinical features of a group of Chinese patients with early infantile epileptic encephalopathy and aimed to provide further insight into the understanding of epilepsy and mental retardation limited to females (EFMR; MIM 300088).Case PresentationWe described three variations in the PCDH19 gene in Chinese patients with epilepsy who developed generalized seizures occurring in clusters with or without triggering by fever. Candidate genes were screened for mutations that cause epilepsy and related paroxysmal or nervous system diseases in the coding exons and intron–exon boundaries using polymerase chain reaction (PCR) of genomic deoxyribonucleic acid (DNA) followed by sequencing. The variations were sequenced using next-generation sequencing technology and verified with first-generation sequencing. Exome sequencing of a multigene epilepsy panel revealed three mutations in the PCDH19 gene in a mosaic male and two unrelated females. These included a frameshift mutation c.1508_1509insT (p.Thr504HisfsTer19), a missense mutation c.1681C > T (p.Pro561Ser) and a nonsense mutation c.918C > G (p.Tyr306Ter). Of the three mutations in the PCDH19 gene associated with early infantile epileptic encephalopathy, the frameshift variation in a mosaic male is novel and de novo, the missense variation is de novo and is the second ever reported in females, and the nonsense variation was inherited from the paternal line and is the first example discovered in a female.ConclusionsThe results from our current study provide new insight into and perspectives for the molecular genetic link between epilepsy and PCDH19 alterations. Moreover, our new findings of the male mosaic variant broaden the spectrum of PCDH19-related epilepsy and provide a new understanding of this complex genetic disorder.