Molecular Inconsistencies in a Fragile X Male with Early Onset Ataxia

Mosaicism for FMR1 premutation (PM: 55–199 CGG)/full mutation (FM: >200 CGG) alleles or the presence of unmethylated FM (UFM) have been associated with a less severe fragile X syndrome (FXS) phenotype and fragile X associated tremor/ataxia syndrome (FXTAS)—a late onset neurodegenerative disorder. We describe a 38 year old male carrying a 100% methylated FM detected with Southern blot (SB), which is consistent with complete silencing of FMR1 and a diagnosis of fragile X syndrome. However, his formal cognitive scores were not at the most severe end of the FXS phenotype and he displayed tremor and ataxic gait. With the association of UFM with FXTAS, we speculated that his ataxia might be related to an undetected proportion of UFM alleles. Such UFM alleles were confirmed by more sensitive PCR based methylation testing showing FM methylation between 60% and 70% in blood, buccal, and saliva samples and real-time PCR analysis showing incomplete silencing of FMR1. While he did not meet diagnostic criteria for FXTAS based on MRI findings, the underlying cause of his ataxia may be related to UFM alleles not detected by SB, and follow-up clinical and molecular assessment are justified if his symptoms worsen

External validation of the DIVA and DIVA3 clinical predictive rules to identify difficult intravenous access in paediatric patients

Background Intravenous (IV) peripheral access is often a difficult procedure in the paediatric ED, causing pain and significant distress. Clinical prediction tools including reproducible variables have been developed to help clinicians identify children at risk of difficult IV access, likely to need additional resources/interventions to maximise success at first attempt. We aimed to externally validate the Difficult IntraVenous Access (DIVA) and DIVA3 scores developed for this purpose. Methods Cross-sectional study of children undergoing IV cannulation by nurses in a tertiary-care paediatric ED. Data were collected at the time of the procedure in a clinical report form. Results Of 440 children included (56.8% males; median age 4.7 years (IQR 1.5-9.5)), 23.4% had a difficult IV access (defined as requiring >1 attempt). Diagnostic accuracy measures for a DIVA cut-off 654 and their 95% CIs were sensitivity 24.3% (16.4% to 33.7%), specificity 92.6% (89.2% to 95.1%), positive and negative predictive value 50.0% (35.3% to 64.5%) and 80.0% (75.7% to 83.9%), respectively. The same measures for the DIVA3 were 22.3% (14.7% to 31.6%), 93.5% (90.3% to 95.9%), 51.1% (35.8% to 66.3%) and 79.8% (75.4% to 83.6%). The area under the receiver operating characteristic curve was 0.652 (95% CI 0.591 to 0.712) for the DIVA and 0.649 (95% CI 0.589 to 0.709) for the DIVA3 score. In patients with DIVA and DIVA3 <4, nurses' prediction of greater difficulty in IV placement and moderate/severe dehydration were common independent predictors of difficult IV at multivariate analysis. Only nurses' prediction of greater difficulty in IV placement were associated with higher odds of difficult cannulation for both DIVA/DIVA3 scores 654. Conclusion We externally validated the DIVA and DIVA3 showing a similar accuracy compared with the DIVA derivation cohort and between DIVA and DIVA3. We identified factors that can help refine further the risk of difficult IV access and support decision making on the best strategy to maximise the chances of cannulation success on first attempt

Missed intracranial injuries are rare in emergency departments using the PECARN head injury decision rules

Purpose: The PECARN head trauma (HT) prediction rules have been developed to guide computed tomography\u2013related decision-making for children with minor HT (mHT). There are currently limited data on the rate of unscheduled revisits to emergency departments (EDs), and initially missed intracranial injuries, in children with mHT initially assessed using the PECARN rules. This study aimed to fill this gap in knowledge. Methods: Clinical charts of children assessed for mHT over a 5-year period at two EDs that implemented the PECARN rules in Italy and France were reviewed retrospectively. Children who returned to EDs for mHT-related, or potentially related complaints, within 1\ua0month of initial assessment were included. Results: The total number of children with mHT presenting for the first time to the EDs of both sites was 11,749. Overall, 180 (1.5%) unscheduled revisits to the EDs occurred for mHT-related or potentially related complaints. Twenty-three of these 180 patients underwent neuroimaging, and seven had an intracranial injury (including one ischemic stroke). Of these, three were hospitalized and none needed neurosurgery or intensive care. Conclusion: Unscheduled revisits for mHT in EDs using the PECARN rules were very uncommon. Initially missed intracranial injuries were rare, and none needed neurosurgery or intensive care

Clinical and Molecular Differences between 4-Year-Old Monozygous Male Twins Mosaic for Normal, Premutation and Fragile X Full Mutation Alleles

This study describes monozygotic (MZ) male twins with fragile X syndrome (FXS), mosaic for normal size (NS: &lt;44 CGGs), premutation (PM: 55&#8211;199 CGG) and full mutation (FM alleles &#8805; 200) alleles, with autism. At 4 years of age chromosomal microarray confirmed monozygosity with both twins showing an XY sex complement. Normal size (30 CGG), PM (99 CGG) and FM (388&#8211;1632 CGGs) alleles were detected in Twin 1 (T1) by standard polymerase chain reaction (PCR) and Southern blot testing, while only PM (99 CGG) and FM (672&#8211;1025) alleles were identified in Twin 2 (T2). At ~5 years, T2 had greater intellectual impairments with a full scale IQ (FSIQ) of 55 and verbal IQ (VIQ) of 59, compared to FSIQ of 62 and VIQ of 78 for T1. This was consistent with the quantitative FMR1 methylation testing, revealing 10% higher methylation at 80% for T2; suggesting that less active unmethylated alleles were present in T2 as compared to T1. AmplideX methylation PCR also identified partial methylation, including an unmethylated NS allele in T2, undetected by standard testing. In conclusion, this report demonstrates significant differences in intellectual functioning between the MZ twins mosaic for NS, PM and FM alleles with partial FMR1 promoter methylation

FMR1 mRNA from full mutation alleles is associated with ABC-C-FX scores in males with fragile X syndrome

Fragile X syndrome (FXS) is caused by a hypermethylated full mutation (FM) expansion with ≥ 200 CGG repeats, and a decrease in FMR1 mRNA and its protein. However, incomplete silencing from FM alleles has been associated with more severe autism features in FXS males. This study compared scores on the Aberrant Behavior Checklist-Community-FXS version (ABC-CFX) in 62 males affected with FXS (3 to 32 years) stratified based on presence or absence of mosaicism and/or FMR1 mRNA silencing. Associations between ABC-CFX subscales and FMR1 mRNA levels, assessed using real-time PCR relative standard curve method, were also examined. The FXS group mosaic for premutation (PM: 55-199 CGGs) and FM alleles had lower irritability (p = 0.014) and inappropriate speech (p < 0.001) scores compared to males with only FM alleles and complete loss of FMR1 mRNA. The PM/FM mosaic group also showed lower inappropriate speech scores compared to the incomplete silencing (p = 0.002) group. Increased FMR1 mRNA levels were associated with greater irritability (p < 0.001), and lower health-related quality of life scores (p = 0.004), but only in the incomplete silencing FM-only group. The findings suggest that stratification based on CGG sizing and FMR1 mRNA levels may be warranted in future research and clinical trials utilising ABC-CFX subscales as outcome measures

Development and usability of a novel interactive tablet app (PediAppRREST) to support the management of pediatric cardiac arrest: Pilot high-fidelity simulation-based study

Background: Pediatric cardiac arrest (PCA), although rare, is associated with high mortality. Deviations from international management guidelines are frequent and associated with poorer outcomes. Different strategies/devices have been developed to improve the management of cardiac arrest, including cognitive aids. However, there is very limited experience on the usefulness of interactive cognitive aids in the format of an app in PCA. No app has so far been tested for its usability and effectiveness in guiding the management of PCA. Objective: To develop a new audiovisual interactive app for tablets, named PediAppRREST, to support the management of PCA and to test its usability in a high-fidelity simulation-based setting. Methods: A research team at the University of Padova (Italy) and human\u2013machine interface designers, as well as app developers, from an Italian company (RE:Lab S.r.l.) developed the app between March and October 2019, by applying an iterative design approach (ie, design\u2013prototyping\u2013evaluation iterative loops). In October\u2013November 2019, a single-center nonrandomized controlled simulation\u2013based pilot study was conducted including 48 pediatric residents divided into teams of 3. The same nonshockable PCA scenario was managed by 11 teams with and 5 without the app. The app user\u2019s experience and interaction patterns were documented through video recording of scenarios, debriefing sessions, and questionnaires. App usability was evaluated with the User Experience Questionnaire (UEQ) (scores range from \u20133 to +3 for each scale) and open-ended questions, whereas participants\u2019 workload was measured using the NASA Raw-Task Load Index (NASA RTLX). Results: Users\u2019 difficulties in interacting with the app during the simulations were identified using a structured framework. The app usability, in terms of mean UEQ scores, was as follows: attractiveness 1.71 (SD 1.43), perspicuity 1.75 (SD 0.88), efficiency 1.93 (SD 0.93), dependability 1.57 (SD 1.10), stimulation 1.60 (SD 1.33), and novelty 2.21 (SD 0.74). Team leaders\u2019 perceived workload was comparable (P=.57) between the 2 groups; median NASA RTLX score was 67.5 (interquartile range [IQR] 65.0-81.7) for the control group and 66.7 (IQR 54.2-76.7) for the intervention group. A preliminary evaluation of the effectiveness of the app in reducing deviations from guidelines showed that median time to epinephrine administration was significantly longer in the group that used the app compared with the control group (254 seconds versus 165 seconds; P=.015). Conclusions: The PediAppRREST app received a good usability evaluation and did not appear to increase team leaders\u2019 workload. Based on the feedback collected from the participants and the preliminary results of the evaluation of its effects on the management of the simulated scenario, the app has been further refined. The effectiveness of the new version of the app in reducing deviations from guidelines recommendations in the management of PCA and its impact on time to critical actions will be evaluated in an upcoming multicenter simulation-based randomized controlled trial

DNA Methylation at Birth Predicts Intellectual Functioning and Autism Features in Children with Fragile X Syndrome

Fragile X syndrome (FXS) is a leading single-gene cause of intellectual disability (ID) with autism features. This study analysed diagnostic and prognostic utility of the Fragile X-Related Epigenetic Element 2 DNA methylation (FREE2m) assessed by Methylation Specific-Quantitative Melt Analysis and the EpiTYPER system, in retrospectively retrieved newborn blood spots (NBS) and newly created dried blood spots (DBS) from 65 children with FXS (~2-17 years). A further 168 NBS from infants from the general population were used to establish control reference ranges, in both sexes. FREE2m analysis showed sensitivity and specificity approaching 100%. In FXS males, NBS FREE2m strongly correlated with intellectual functioning and autism features, however associations were not as strong for FXS females. Fragile X mental retardation 1 gene (FMR1) mRNA levels in blood were correlated with FREE2m in both NBS and DBS, for both sexes. In females, DNAm was significantly increased at birth with a decrease in childhood. The findings support the use of FREE2m analysis in newborns for screening, diagnostic and prognostic testing in FXS