Analysis of overlapping heterozygous novel submicroscopic CNVs and FANCA-VPS9D1 fusion transcripts in a Fanconi anemia patient.

Fanconi anemia (FA) is the most common inherited bone marrow failure syndrome with 22 FA-related genes identified to date. Fragment deletions are frequently occurring aberrances accounting for ~30% of pathogenic variants in them, especially in FANCA, most of which are the results of genomic rearrangement events mediated by the highly concentrated Alu elements interspersing in it. Owing to the capability to detect genome-wide copy number variations (CNVs) with the resolution of 400 kb or larger, cytogenomic microarray is the most widely used method in the clinic currently. However, thereis still a technical gap in the detection of CNVs ranging from hundreds of bp to hundreds of kb between microarray, Sanger sequencing, and direct targeted high-throughput sequencing (THS). Here, we report the analysis of overlapping heterozygous novel submicroscopic deletions of FANCA gene in a FA patient, and discuss the mechanism of the deletions and the formation of FANCA-VPS9D1 fusion transcripts. Our results support that both low-coverage whole-genome sequencing and bioinformatics analysis of THS data for submicroscopic CNVs surpass SNP array in efficacy and accuracy.

Molecular Characteristics of Carbapenem-Resistant Enterobacter cloacae in Ningxia Province, China.

The emergence of carbapenem-resistant Enterobacteriaceae (CRE) has become a major public health concern worldwide and a new challenge in the treatment of infectious diseases. The molecular characteristics of Enterobacter cloacae in Ningxia China are unknown. In this study, we reported 10 carbapenem-resistant E. cloacae isolates from the General Hospital of Ningxia Medical University, the largest university hospital in Ningxia between January 2012 and December 2013. Bacteria isolates were identified by Vitek2 compact and the identity of non-duplicate E. cloacae isolates was further confirmed by PCR and sequencing. The drug susceptibility and phenotype identification of these isolates were analyzed by agar dilution method, modified Hodge test (MHT), and EDTA synergy test. Beta-lactamase (bla) genes blaNDM-1 was found in 8 out of 10 isolates. Most isolates harbored multiple resistance genes including blaESBL, blaAmpC, quinolones, aminoglycosides, and disinfectant resistance genes. Pulsed field gel electrophoresis (PFGE) showed that these E. cloacae isolates were grouped into 6 clusters based on a cutoff of 80% genetic similarity. In conjugative assay, 9 out of 10 isolates transferred carbapenem-resistant genes to Escherichia coli. Our study has revealed that NDM-1-producing isolates are the most prevalent carbapenem-resistant E. cloacae in Ningxia. These isolates also carry several other carbapenem-resistant genes and can transfer these genes to other bacteria through conjugation. These findings highlight an urgent need to monitor these isolates to prevent their further spread in this region.