Deletion of P2 promoter of GJB1 gene a cause of Charcot-Marie-Tooth disease

X-linked Charcot-Marie-Tooth disease (CMT) is the second most common cause of CMT, and is usually caused by mutations in the gap junction protein beta 1 (GJB1) gene. This gene has nerve specific P2 promoter that work synergistically with SOX10 and EGR2 genes to initiate transcription. Mutation in this region is known to cause Schwann cell dysfunction. A single large family of X linked peripheral neuropathy was identified in our practice. Next generation sequencing for targeted panel assay identified an upstream exon-splicing deletion identified extending from nucleotide c.-5413 to approximately - c.-49. This matches the sequence of 32 nucleotides at positions c.*218-*249 in the 3'UTR downstream of the GJB1 gene. The deleted fragment included the entire P2 promoter region. The deletion segregated with the disease. To our knowledge a deletion of the P2 promoter alone as a cause of CMT has not been reported previously.

MR Fingerprinting of Adult Brain Tumors: Initial Experience

BACKGROUND AND PURPOSE

MR fingerprinting allows rapid simultaneous quantification of T1 and T2 relaxation times. This study assessed the utility of MR fingerprinting in differentiating common types of adult intra-axial brain tumors.

MATERIALS AND METHODS

MR fingerprinting acquisition was performed in 31 patients with untreated intra-axial brain tumors: 17 glioblastomas, 6 World Health Organization grade II lower grade gliomas, and 8 metastases. T1, T2 of the solid tumor, immediate peritumoral white matter, and contralateral white matter were summarized within each ROI. Statistical comparisons on mean, SD, skewness, and kurtosis were performed by using the univariate Wilcoxon rank sum test across various tumor types. Bonferroni correction was used to correct for multiple-comparison testing. Multivariable logistic regression analysis was performed for discrimination between glioblastomas and metastases, and area under the receiver operator curve was calculated.

RESULTS

Mean T2 values could differentiate solid tumor regions of lower grade gliomas from metastases (mean, 172 ± 53 ms, and 105 ± 27 ms, respectively; P = .004, significant after Bonferroni correction). The mean T1 of peritumoral white matter surrounding lower grade gliomas differed from peritumoral white matter around glioblastomas (mean, 1066 ± 218 ms, and 1578 ± 331 ms, respectively; P = .004, significant after Bonferroni correction). Logistic regression analysis revealed that the mean T2 of solid tumor offered the best separation between glioblastomas and metastases with an area under the curve of 0.86 (95% CI, 0.69-1.00; P < .0001).

CONCLUSIONS

MR fingerprinting allows rapid simultaneous T1 and T2 measurement in brain tumors and surrounding tissues. MR fingerprinting-based relaxometry can identify quantitative differences between solid tumor regions of lower grade gliomas and metastases and between peritumoral regions of glioblastomas and lower grade gliomas.

Afterwords: The Quality of Medical Accident Investigations and Analyses

Adverse events, or accidents, in healthcare can have significant clinical outcomes including loss of property, health (morbidity), and life (mortality). Healthcare accidents have features that make post-event investigations particularly difficult. The investigation and analysis of medical accidents is intended to discover information that explains the nature and cause of what occurred in the interest of preventing or minimizing future loss. The thorough, objective investigation of medical adverse events rarely happens due to the complexity of the environment, litigation, risk, and socio-political implications. Special concerns can undermine investigation depth, breadth, and quality. Healthcare's distinct difference from other high hazard sectors such as aviation and nuclear power requires a unique approach. Healthcare accident examination requires detailed domain knowledge and the use of diverse investigation methods. This paper describes the current state of medical accident analysis, obstacles to understanding such accidents and strategies to overcome them, as well as future investigation and analysis approaches.

Determining performance characteristics of an NGS-based HLA typing method for clinical applications

This study presents performance specifications of an in-house developed human leukocyte antigen (HLA) typing assay using next-generation sequencing (NGS) on the Illumina MiSeq platform. A total of 253 samples, previously characterized for HLA-A, -B, -C, -DRB1 and -DQB1 were included in this study, which were typed at high-resolution using a combination of Sanger sequencing, sequence-specific primer (SSP) and sequence-specific oligonucleotide probe (SSOP) technologies and recorded at the two-field level. Samples were selected with alleles that cover a high percentage of HLA specificities in each of five different race/ethnic groups: European, African-American, Asian Pacific Islander, Hispanic and Native American. Sequencing data were analyzed by two software programs, Omixon's target and GenDx's NGSengine. A number of metrics including allele balance, sensitivity, specificity, precision, accuracy and remaining ambiguity were assessed. Data analyzed by the two software systems are shown independently. The majority of alleles were identical in the exonic sequences (third field) with both programs for HLA-A, -B, -C and -DQB1 in 97.7% of allele determinations. Among the remaining discrepant genotype calls at least one of the analysis programs agreed with the reference typing. Upon additional manual analysis 100% of the 2530 alleles were concordant with the reference HLA genotypes; the remaining ambiguities did not exceed 0.8%. The results demonstrate the feasibility and significant benefit of HLA typing by NGS as this technology is highly accurate, eliminates virtually all ambiguities, provides complete sequencing information for the length of the HLA gene and forms the basis for utilizing a single methodology for HLA typing in the immunogenetics labs.

Investigations of in vitro bioaccessibility from interesterified stearic and oleic acid-rich blends

Interesterification was previously found to impact stearic acid absorption in a randomized cross-over study, when human volunteers consumed a 70 : 30 wt% high-oleic sunflower and canola stearin blend (NIE) compared to the same blend which had undergone either chemical (CIE) or enzymatic (EIE) interesterification.

Utilizing functional lumen imaging probe topography to evaluate esophageal contractility during volumetric distention: a pilot study

BACKGROUND

The functional lumen imaging probe (FLIP) measures luminal cross-sectional area and pressure during volumetric distension. By applying novel customized software to produce FLIP topography plots, organized esophageal contractility can be visualized and analyzed. We aimed to describe the stimulus thresholds and contractile characteristics for distension-induced esophageal body contractility using FLIP topography in normal controls.

METHODS

Ten healthy controls were evaluated during endoscopy with FLIP. During stepwise bag distension, simultaneous intra-bag pressure and luminal diameter measurements were obtained and exported to a MatLab program to generate FLIP topography plots. The distension volume, intra-bag pressure, and maximum esophageal body diameters were measured for the onset and cessation of repetitive antegrade contractions (RACs). Contraction duration, interval, magnitude, and velocity were measured at 8 and 3-cm proximal to the esophagogastric junction.

KEY RESULTS

Eight of ten subjects demonstrated RACs at a median onset volume of 29 mL (IQR: 25-38.8), median intra-bag pressure of 10.7 mmHg (IQR: 8.6-15.9), and median maximum esophageal body diameter of 18.5 mm (IQR: 17.5-19.6). Cessation of RACs occurred prior to completion of the distension protocol in three of the eight subjects exhibiting RACs. Values of the RAC-associated contractile metrics were also generated to characterize these events.

CONCLUSIONS & INFERENCES

Distension-induced esophageal contractions can be assessed utilizing FLIP topography. RACs are a common finding in asymptomatic controls in response to volume distention and have similar characteristics to secondary peristalsis and repetitive rapid swallows.

Identification and characterization of a novel HLA-B hybrid allele, B*08:132 with Next Generation Sequencing

The new allele is a hybrid between B*08:01:01 and B*42:01:01.

The experience of disabled children as inpatients: a structured review and synthesis of qualitative studies reporting the views of children, parents and professionals

Disabled children are a broad group that includes those with complex, special or additional health needs as a result of chronic physical, cognitive, communication or behavioural problems. These children are more frequently admitted to hospital than other children; however, there appears to be relatively little research on their experience as inpatients. The aim of this structured review and synthesis was to integrate findings from qualitative studies reporting the experience of disabled children when they are hospital inpatients. Inclusion criteria were: qualitative studies that focused on the experience of children less than 18 years old, with a chronic health condition or neurodisability, during an inpatient stay. Studies of outpatient episodes or intensive care units were excluded. A systematic search identified relevant abstracts, selected papers were reviewed and data were extracted. The synthesis involved elucidating and integrating common themes. Eight relevant papers were identified; data were gathered from children, parents and staff. Communication between children and staff was a dominant theme and comprised giving the child information about their condition and appropriate involvement of the child/young person in discussions and decision making that affected them. Also important was communication between parents and staff, particularly around the division of care for their child. Other themes included emotions, particularly fears, the ward environment and confidence in staff. The review suggests that disabled children's experience as inpatients is not always optimal. Improving the communication skills of ward staff and providing information to disabled children and their families would improve disabled children's experience when they are inpatients.