[A novel mutation of SCN4A gene causes hypokalemic periodic paralysis in a Chinese family].

Objective: To report a Chinese family with hypokalemic periodic paralysis (HOKPP) and investigate the clinical and pathogenic gene characteristics of the family. Methods: The clinical, electrophysiological and pathological data of the proband of the family were analyzed, and the information of the family was investigated in detail. The peripheral venous blood of the six members of the family was collected and their genomic DNA was extracted. The genes related to periodic paralysis analysis of the proband were performed by the second generation sequencing. The pathogenicity of the mutant protein was respectively analyzed by the bioinformatics software SIFT, Polyphen2 and Mutation Tasker. The cosegregation analysis of phenotype and genotype of the family was performed by the first generation sequencing. Results: There were 3 patients in the family with the onset age of 21 to 42 years old. All the patients manifested with vomiting as the first symptoms, then presented with muscle weakness accompanied by muscle soreness. The muscle weakness gradually relieved in 3 to 5 days. Creatine kinase (CK) of the proband significantly increased. Electromyographic exercise test was positive, however, electromyography and muscle pathological analysis were normal. The genes related to periodic paralysis analysis of the proband found a novel mutation (c.2458A>T (p.N.820Y)) of SCN4A gene which was located in the conservative region. The function analysis showed it was a pathogenic mutation. Moreover, the first generation sequencing confirmed that the mutation was cosegregated with patients in the family. Meanwhile, it was found that the proband's son carried the same mutation, but without any symptom, indicating that he was a pre-symptomatic patient. Conclusions: Vomiting can be one of the symptoms of the patients with HOKPP. The novel mutation of SCN4A gene c.2458 A>T is the pathogenic mutation of the family. Patients with periodic paralysis should be tested for blood potassium and genes as early as possible to facilitate early diagnosis and genetic counseling.

Evaluation of the molecular Xpert Xpress Flu/RSV assay vs. Alere i Influenza A & B assay for rapid detection of influenza viruses.

A new FDA-approved Xpert Xpress Flu/RSV assay has been released for rapid influenza virus detection. We collected 134 nasopharyngeal specimens to compare the diagnostic performance of the Xpert assay and the Alere i Influenza A & B assay for influenza A and B virus detection. The Xpert assay demonstrated 100% and 96.3% sensitivity to influenza A and influenza B virus respectively. Its specificity was 100% for both viruses. The Alere i assay demonstrated slightly lower sensitivity but similar specificity to the Xpert Xpress assay. Although the Xpert assay (30 min) required longer processing time than the Alere assay (15 min), the handling procedure of the Alere assay was more complicated than the Xpert assay. As the GenXpert system has higher throughput than the Alere system, it is more suitable for hospital clinical laboratories. Overall, the new Xpert Xpress Flu/RSV assay is a reliable and useful tool for rapid influenza detection.

Phenotypes and cellular effects of GJB1 mutations causing CMT1X in a cohort of 226 Chinese CMT families.

The aim of this study is to explore the phenotypic and genotypic features of X-linked Charcot-Marie-Tooth (CMT) disease in the mainland of China and to study the cellular effects of six novel Gap junction protein beta-1 variants. We identified 25 missense and 1 non-sense mutations of GJB1 in 31 unrelated families out of 226 CMT families. The frequency of GJB1 mutations was 13.7% of the total and 65% of intermediate CMT. Six novel GJB1 variants (c.5A>G, c.8G>A, c.242T>C, c.269T>C, c.317T>C and c.434T>G) were detected in six unrelated intermediate CMT families. Fluorescence revealed that HeLa cells transfected with EGFP-GJB1-V74M, EGFP-GJB1-L81P or EGFP-GJB1-L90P had diffuse endoplasmic reticulum staining, HeLa cells transfected with EGFP-GJB1-L106P had diffuse intracellular staining, and HeLa cells transfected with EGFP-GJB1-N2S had cytoplasmic and nuclear staining. The distribution of Cx32 in HeLa cells transfected with EGFP-GJB1-F145C was similar to that of those transfected with wild-type (WT). These six variants resulted in a higher percentage of apoptosis than did WT as detected by flow cytometry and Hoechst staining. In conclusion, mutation screening should be first performed in intermediate CMT patients, especially those with additional features. The novel GJB1 variants c.5A>G, c.8G>A, c.242T>C and c.269T>C are considered pathogenic, and c.317T>C and c.434T>G are classified as probably pathogenic.

Genome-wide comparison of AP2/ERF superfamily genes between Gossypium arboreum and G. raimondii.

The APETALA2/ethylene response factor (AP2/ERF) transcription factor superfamily is known to regulate diverse processes of plant development and stress responses. We conducted a genome-wide analysis of the AP2/ERF gene in Gossypium arboreum and G. raimondii. Using RPSBLAST and HMMsearch, a total of 271 and 269 AP2/ERF genes were identified in the G. arboreum and G. raimondii genomes, respectively. A phylogenetic analysis classified diploid Gossypium spp AP2/ERF genes into 4 families and 16 subfamilies. Orthologous genes predominated the terminal branch of the phylogenetic tree. Physical mapping showed at least 30% of AP2/ERF genes clustered together. A high level of intra- and inter-species collinearity involving AP2/ERF genes was observed, indicating common (before species divergence) or parallel (after species divergence) segmental duplications, along with tandem duplications, resulting in the species-specific expansion of AP2/ERF genes in diploid Gossypium species. Motif analyses of the AP2/ERF proteins revealed that motif arrangements were highly diverse among subfamilies, but shared by orthologous gene pairs. An examination of nucleotide divergence of AP2/ERF coding regions identified small and non-significant sequence differences among orthologs. Expression profiling of AP2/ERF orthologous gene pairs showed similar abundance levels of orthologous copies between G. arboreum and G. raimondii. Thus, cotton species possess abundant and diverse AP2/ERF genes, resulting from tandem and segmental duplications. Protein and nucleotide sequence and mRNA expression analyses revealed symmetrical evolution, indicating that most AP2/ ERF genes may not have undergone significant biochemical and morphological divergence between sister species. Our study provides detailed insights into the evolutionary characteristics and functional importance of AP2/ERF genes, and could aid in the genetic improvement of agriculturally significant crops in this genus.

A novel hemizygous SACS mutation identified by whole exome sequencing and SNP array analysis in a Chinese ARSACS patient.

The array of autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) has expanded worldwide after the first description in the Charlevoix-Saguenay region of Québec. Here, we report a Chinese ARSACS patient presenting progressive peripheral neuropathy (CMTNS2=15) with horizontal gaze nystagmus and mild spastic gait. Genetic studies including whole exome sequencing (WES), Sanger sequencing and single nucleotide polymorphism (SNP) array analysis revealed a novel hemizygous nonsense mutation (c.11803C>T, p.Gln3935X) of SACS and a 1.33Mb deletion involved in SACS on chromosome 13q12.12 in the patient. Our findings highlight the necessity of SACS mutation screening in the gene panel of inherited peripheral neuropathies, and stress the need of testing copy number variation (CNV) in SACS mutation screening.

Identification and analysis of the TIFY gene family in Gossypium raimondii.

The highly conserved TIFY domain is included in the TIFY protein family of transcription factors, which is important in plant development. Here, 28 TIFY family genes were identified in the Gossypium raimondii genome and classified into JAZ (15 genes), ZML (8), PPD (3), and TIFY (2). The normal (TIF[F/Y]XG) motif was dominant in the TIFY family, excluding the ZML subfamily, in which TLSFXG was prevalent. TIFY family genes were unevenly distributed in the G. raimondii genome, with TIFY clusters present on chromosome 9. Phylogenetic analysis indicated abundant variations in the G. raimondii TIFY family, which were most closely related to those in Theobroma cacao among 5 species. Exon-intron organization and intron phases were homologous within each subfamily, correlating with their phylogeny. Intra-species synteny analyses indicated that genomic duplication contributed to the expansion of the TIFY family. Inter-species synteny analyses indicated that synteny regions involved in G. raimondii TIFY family genes were also present in the comparison of G. raimondii vs Arabidopsis thaliana or T. cacao, signifying that these genes had common ancestors and play the same or similar roles in biological processes. Greater synteny was present in the comparison of G. raimondii vs T. cacao than of G. raimondii vs A. thaliana. The expression patterns of TIFY family genes were characterized and most TIFY family genes were indicated to be involved in fiber development. Our study provides new data related to the evolution of TIFYs and their role as important regulators of transcription; these data can be useful for fiber development.

Huntingtin gene CAG repeat numbers in Chinese patients with Huntington's disease and controls.

BACKGROUND AND PURPOSE: Huntington's disease is due to a CAG triplet repeat elongation in the huntingtin gene. Boundaries in CAG numbers have been found between healthy people with and without risk to pass the disorder to the next generation, and between people without, with a mild, or with a fully penetrant phenotype. These data have been generated in western populations and it is not clear whether they are also valid amongst Chinese. METHODS: In order to establish normative data in the huntingtin gene for Chinese people, 966 chromosomes from normal controls were tested. Further, the range of CAG repeats was examined in a cohort from six centres and a total of 368 patients with the disease were included. RESULTS: The CAG triplet repeat range in normal controls was between 9 and 35 (mean 18.9, SD 2.57). Triplets in the range between 26 and 35 were found in 2.5%. In the patient cohort, triplet repeats in the shorter allele were between 8 and 37 (mean 17.7, SD 1.6). In the longer allele, a range between 36 and 120 was found. There was a negative correlation (-0.65, r = 0.42) between age at onset and the number of triplet repeats in the larger allele. The mean age at onset was 38 years, with a range between 2 and 70 years. In 23 patients (6%) a childhood or juvenile onset was noted. CONCLUSION: These data show comparable ranges of huntingtin gene CAG triplet repeats in normal people and in patients with Huntington's disease as in western populations.

Outbreak of microsporidial keratoconjunctivitis with rugby sport due to soil exposure.

AIMS: To investigate a cluster of microsporidial keratoconjunctivitis in 33 eyes of 25 previously healthy paediatric and teenage individuals after a rugby match. METHODS: An observational case series was reported. Analysis of medical record of patients with microsporidial keratoconjunctivitis, who presented within May 2012, was performed. All patients were treated by a single ophthalmologist with a standardized topical regime, including a fluoroquinolone (moxifloxacin) and an antiseptic (Brolene or Desomedine). Five eyes received corneal scrapings. RESULTS: The mean age was 13.36 years (range 5-16). All patients have participated in a rugby match on 21-22 April 2012. The onset of symptoms ranged from 10 to 30 days post exposure. All eyes had multiple superficial coarse punctate keratitis. Four (12%) eyes presented with keratic precipitates. One (3%) eye had intraocular pressure of 27 mm Hg. Microscopic examination of corneal scrapings with modified trichrome or calcofluor white (CFW) fluorescent staining was unremarkable but subsequent PCR test was positive for the small subunit rRNA gene of Vittaforma corneae in three out of five eyes. Sequencing of the PCR product of 1150 bp showed 96-100% identity with the Indian or Singaporean strains of V. corneae. After treatment, all eyes healed without sequel. CONCLUSIONS: The first outbreak of microsporidial keratoconjunctivitis in paediatric and teenage individuals with a rugby match is reported. A standardized topical regime, including a fluoroquinolone (moxifloxacin) and an antiseptic (Brolene or Desomedine), seems to be safe and effective, and requires validation in future treatment trials.

Differential processing of neuropeptide proprotein in human breast adenocarcinoma.

BACKGROUND: The processing of proprotein convertase (PC)-mediated neuropeptide plays a very important role in carcinogenesis and tumor proliferation. AIM: To investigate proneuropeptide processing mechanism in tumorigenesis and tumor proliferation. MATERIALS AND METHODS: The expression and processing profiles of PC1, carboxypeptidase E (CPE), PC2, GHRH, or neuropeptide Y (NPY) gene and protein level were investigated between 42 human breast tumor tissues and 21 tumor-adjacent normal tissues. RESULTS: Gene analyses indicated that the proPC1, CPE, or preproNPY gene had higher expression in the breast tumor tissues, whereas the proPC2 or preproGHRH gene showed lower expression in the tissues. Protein analyses showed that the proPC1, PC1, CPE, GHRH, and preproNPY proteins were upregulated in the tumor tissues, whereas the proPC2, PC2, preproGHRH, and NPY proteins were down-regulated in them. The tissue results were highly corroborated with the serum data from the tumor patients and healthy women. CONCLUSIONS: The higher PC1 and CPE expressions as well as the transformation of more proGHRH into active GHRH peptide suggest stronger PC1/CPE-mediated neuropeptide processing in the tumor, whereas the lower PC2 expression as well as the transformation of less proNPY into active NPY peptide suggests a weak PC2-mediated processing in it. The alterations of the convertase expressions and processing show that there is a differential proprotein processing system in the tumor, which leads to the abnormal distributions of species, ratio, and concentration of (pro)peptide(s) in the microenvironment of cells. The latter may contribute to cancer progression.

Novel PRRT2 mutations in paroxysmal dyskinesia patients with variant inheritance and phenotypes.

Paroxysmal dyskinesias (PDs) are a group of episodic movement disorders with marked variability in clinical manifestation and potential association with epilepsy. PRRT2 has been identified as a causative gene for PDs, but the phenotypes and inheritance patterns of PRRT2 mutations need further clarification. In this study, 10 familial and 21 sporadic cases with PDs and PDs-related phenotypes were collected. Genomic DNA was screened for PRRT2 mutations by direct sequencing. Seven PRRT2 mutations were identified in nine (90.0%) familial cases and in six (28.6%) sporadic cases. Five mutations are novel: two missense mutations (c.647C>G/p.Pro216Arg and c.872C>T/p.Ala291Val) and three truncating mutations (c.117delA/p.Val41TyrfsX49, c.510dupT/p.Leu171SerfsX3 and c.579dupA/p.Glu194ArgfsX6). Autosomal dominant inheritance with incomplete penetrance was observed in most of the familial cases. In the sporadic cases, inheritance was heterogeneous including recessive inheritance with compound heterozygous mutations, inherited mutations with incomplete parental penetrance and de novo mutation. Variant phenotypes associated with PRRT2 mutations, found in 36.0% of the affected cases, included febrile convulsions, epilepsy, infantile non-convulsive seizures (INCS) and nocturnal convulsions (NC). All patients with INCS or NC, not reported previously, displayed abnormalities on electroencephalogram (EEG). No EEG abnormalities were recorded in patients with classical infantile convulsions and paroxysmal choreoathetosis (ICCA)/paroxysmal kinesigenic dyskinesia (PKD). Our study further confirms that PRRT2 mutations are the most common cause of familial PDs, displaying both dominant and recessive inheritance. Epilepsy may occasionally occur in ICCA/PKD patients with PRRT2 mutations. Variant phenotypes INCS or NC differ from classical ICCA/PKD clinically and electroencephalographically. They have some similarities with, but not identical to epilepsy, possibly represent an overlap between ICCA/PKD and epilepsy.

PLA2G6 gene mutation in autosomal recessive early-onset parkinsonism in a Chinese cohort.

OBJECTIVE: Mutations in the PLA2G6 gene at the PARK14 locus have been reported in complicated parkinsonism. To assess the prevalence of and phenotypes associated with PLA2G6 gene mutations, we screened PLA2G6 mutations in a cohort of patients with autosomal recessive early-onset parkinsonism (AREP). METHODS: We selected 12 families with AREP in which the Parkin, PINK1, DJ-1, ATP13A2, and FBXO7 gene mutations had been previously excluded. All patients came from the mainland of China. The entire PLA2G6 coding region and exon-intron boundaries were sequenced from genomic DNA templates. We then performed PET studies on individuals in the pedigree with a homozygous PLA2G6 mutation, and investigated the enzyme activity level of the mutation. RESULTS: A homozygous missense mutation, c.G991T (p.D331Y), was identified in an autosomal recessive case. A younger sister of the p.D331Y-carrying patient was also homozygous for the mutation, but with no extrapyramidal symptoms. A PET study showed a substantial reduction in dopamine transporter (DAT) binding in the p.D331Y patient, and a slight reduction in DAT binding in his sister. In vitro, we experimentally demonstrate that the D331Y mutation caused an approximately 70%reduction in enzyme activity. CONCLUSIONS: We have confirmed that the PLA2G6 gene allocated PARK14 locus and is associated with AREP.

Q fever: underdiagnosed in Hong Kong?

We report the first imported case of chronic Q fever with multi-organ involvement seen in Hong Kong. Although the disease is found worldwide, its chronic form is very rare in our locality. Familiarity with the clinical presentation, useful diagnostic tools, and appropriate treatment is necessary for the prevention of the serious morbidity and mortality associated with chronic Q fever. To the best of our knowledge, this article represents the first comprehensive review to compare the local experience with Q fever with international data, and establishes a management approach for this unusual infectious disease while suggesting possible explanations for its exceptionally low incidence in this locality.

Antimicrobial stewardship program directed at broad-spectrum intravenous antibiotics prescription in a tertiary hospital.

The antimicrobial stewardship program (ASP) is a major strategy to combat antimicrobial resistance and to limit its expenditure. We have improved on our existing ASP to implement a sustainable and cost-effective two-stage immediate concurrent feedback (ICF) model, in which the antimicrobial prescription is audited by two part-time infection control nurses at the first stage, followed by "physician ICF" at the second stage. In January 2005, an ASP focused on broad-spectrum intravenous antibiotics was implemented. All in-patients, except from the intensive care, bone marrow transplantation, liver transplantation, pediatric, and private units, being treated with broad-spectrum intravenous antibiotics were included. The compliance to ICF and "physician ICF", antibiotics usage density measured by expenditure and defined daily doses (DDD) were recorded and analyzed before and after the ASP. The overall conformance rate to antibiotic prescription guidelines was 79.4%, while the conformance to ICF was 83.8%. Antibiotics consumption reduced from 73.06 (baseline, year 2004) to 64.01 (year 2007) per 1,000 patient bed-day-occupancy. Our model can be easily applied even in the clinical setting of limited resources.

Mutation analysis of the TATA box-binding protein (TBP) gene in Chinese Han patients with spinocerebellar ataxia.

Spinocerebellar ataxia type 17 (SCA17) is a rare autosomal dominant progressive neurodegenerative disease caused by the CAG/CAA expansion in the TATA box-binding protein (TBP) gene. This study aimed to assess the frequency of SCA17 in patients from mainland China. Analysis of CAG/CAA expansion in this gene was performed in 263 patients consisting of 100 probands with dominantly inherited ataxias and 163 patients with sporadic ataxias. Abnormal expansion of CAG/CAA repeats in the SCA17 locus was found in a proband and her younger sister. To our knowledge, we are providing the first kindred analysis of SCA17 in mainland China.

Comparative host gene transcription by microarray analysis early after infection of the Huh7 cell line by SARS coronavirus and human coronavirus 229E.

During the early stages of infection, SARS-CoV produces more severe perturbation of host cell gene expression in a human epithelial cell line of liver origin than the HCoV-229E.

Effect of antibiotics on the bacterial load of meticillin-resistant Staphylococcus aureus colonisation in anterior nares.

Prevalence of hospital-acquired meticillin-resistant Staphylococcus aureus (MRSA) infection or colonisation has been associated with antimicrobial consumption. The impact of antibiotic treatment on nasal colonisation is unknown. We conducted a three-month prospective study of 116 patients with extranasal MRSA infection or colonisation, whose nasal MRSA bacterial loads were determined during and after various antibiotic courses over a period of three weeks. Environmental swabs were also taken from the near patient environment. Concomitant nasal MRSA carriage was observed in 76.7% of extranasal MRSA-colonised or -infected patients. The median nasal MRSA bacterial load increased significantly from 2.78 (range 0-6.15) to 5.30 (range 2.90-8.41) log(10) cfu per swab (cfu/swab) (P<0.001) over 21 days during beta-lactam therapy. It also increased from 0 (range 0-4.00) to 4.30 (range 0-7.46) log(10)cfu/swab (P=0.039) over 14 days during fluoroquinolone therapy. Median bacterial loads were significantly higher for beta-lactam- and fluoroquinolone-treated patients on day 7 [4.78, range 0-7.30], day 14 [4.30, range 0-7.60] and day 21 [5.30, range 2.90-8.41] than controls not receiving antibiotics (P<0.05). These loads then decreased by 2-5log(10)cfu/swab 2 weeks after discontinuation of antibiotics. The environment of patients receiving beta-lactam agents (relative risk: 3.55; 95% confidence interval: 1.30-9.62; P=0.018) or fluoroquinolones (4.32; 1.52-12.31; P=0.008) demonstrated more MRSA contamination than the environment around control patients (0.79; 0.67-0.93; P=0.002). Patients on beta-lactam or fluoroquinolone therapy have increased incidence of MRSA colonisation and higher nasal bacterial loads, and appear to spread their MRSA into the near patient environment.