Bi-allelic variants in the mitochondrial RNase P subunit PRORP cause mitochondrial tRNA processing defects and pleiotropic multisystem presentations.

Human mitochondrial RNase P (mt-RNase P) is responsible for 5' end processing of mitochondrial precursor tRNAs, a vital step in mitochondrial RNA maturation, and is comprised of three protein subunits: TRMT10C, SDR5C1 (HSD10), and PRORP. Pathogenic variants in TRMT10C and SDR5C1 are associated with distinct recessive or x-linked infantile onset disorders, resulting from defects in mitochondrial RNA processing. We report four unrelated families with multisystem disease associated with bi-allelic variants in PRORP, the metallonuclease subunit of mt-RNase P. Affected individuals presented with variable phenotypes comprising sensorineural hearing loss, primary ovarian insufficiency, developmental delay, and brain white matter changes. Fibroblasts from affected individuals in two families demonstrated decreased steady state levels of PRORP, an accumulation of unprocessed mitochondrial transcripts, and decreased steady state levels of mitochondrial-encoded proteins, which were rescued by introduction of the wild-type PRORP cDNA. In mt-tRNA processing assays performed with recombinant mt-RNase P proteins, the disease-associated variants resulted in diminished mitochondrial tRNA processing. Identification of disease-causing variants in PRORP indicates that pathogenic variants in all three subunits of mt-RNase P can cause mitochondrial dysfunction, each with distinct pleiotropic clinical presentations.

Does E-learning Facilitate Medical Education in Pediatric Neurology?

BACKGROUND: E-learning has become commonplace in medical education. Incorporation of multimedia, clinical cases, and interactive elements has increased its attractiveness over textbooks. Although there has been an expansion of e-learning in medicine, the feasibility of e-learning in pediatric neurology is unclear. This study evaluates knowledge acquisition and satisfaction using pediatric neurology e-learning compared to conventional learning. METHODS: Residents of Canadian pediatrics, neurology, and pediatric neurology programs and medical students from Queens University, Western University, and the University of Ottawa were invited to participate. Learners were randomly assigned two review papers and two ebrain modules in a four-topic crossover design. Participants completed pre-tests, experience surveys, and post-tests. We calculated the median change in score from pre-test to post-test and constructed a mixed-effects model to determine the effect of variables on post-test scores. RESULTS: In total, 119 individuals participated (53 medical students; 66 residents). Ebrain had a larger positive change than review papers in post-test score from pre-test score for the pediatric stroke learning topic but a smaller positive change for Duchenne muscular dystrophy, childhood absence epilepsy, and acute disseminated encephalomyelitis. Learning topics showed statistical relationship to post-test scores (p = 0.04). Depending on topic, 57-92% (N = 59-66) of respondents favored e-learning over review article learning. CONCLUSIONS: Ebrain users scored higher on post-tests than review paper users. However, the effect is small and it is unclear if it is educationally meaningful. Although the difference in scores may not be substantially different, most learners preferred e-learning. Future projects should focus on improving the quality and efficacy of e-learning modules.

Variability in Newborn Screening Across Canada: Spinal Muscular Atrophy and Beyond.

BACKGROUND: Newborn screening (NBS) identifies infants with severe, early-onset diseases, enabling early diagnosis and treatment. In Canada, decisions regarding disease inclusion in NBS programs occur at the provincial level, which leads to variability in patient care. We aimed to determine whether important differences exist in NBS programs across provinces and territories. Given that spinal muscular atrophy (SMA) is the most recent disease added to NBS programs, we hypothesized that its inclusion would show interprovincial variability and be more likely in provinces already screening for a greater number of diseases. METHODS: We conducted a cross-sectional survey of all NBS labs in Canada to understand: 1) what conditions were included in their program; 2) what genetic-based testing was performed and; 3) if SMA was included. RESULTS: All NBS programs (N = 8) responded to this survey by June 2022. There was a 2.5-fold difference in the number of conditions screened (N = 14 vs N = 36) and a 9-fold difference in the number of conditions screened by gene-based testing. Only nine conditions were common to all provincial NBS programs. NBS for SMA was performed in four provinces at the time of our survey, with BC recently becoming the fifth province to add SMA to their NBS on October 1, 2022. Currently, 72% of Canadian newborns are screened for SMA at birth. CONCLUSION: Although healthcare in Canada is universal, its decentralization gives rise to regional differences in NBS programs which creates inequity in the treatment, care, and potential outcomes of affected children across provincial jurisdictions.

Quick, Effective Screening Tasks Identify Children With Medical Conditions or Disabilities Needing Physical Literacy Support.

PURPOSE: This study evaluated screening tasks able to identify children with medical conditions or disabilities who may benefit from physical literacy. METHOD: Children completed ≤20 screening tasks during their clinic visit and then the Canadian Assessment of Physical Literacy (2nd edition) at a separate visit. Total Canadian Assessment of Physical Literacy scores <30th percentile were categorized as potentially needing physical literacy support. Receiver operator characteristic curves identified assessment cut points with 80% sensitivity and 40% specificity relative to total physical literacy scores. RESULTS: 223 children (97 girls; 10.1 [2.6] y) participated. Physical activity adequacy, predilection, and physical competence achieved ≥80% sensitivity and ≥40% specificity in both data sets. Adequacy ≤ 6.5 had 86% to 100% sensitivity and 48% to 49% specificity. Daily screen time >4.9 hours combined with Adequacy ≤6.15 had 88% to 10% sensitivity and 53% to 56% specificity. CONCLUSIONS: Activity adequacy, alone or with screen time, most effectively identified children likely to benefit from physical literacy support. Adequacy and screen time questionnaires are suitable for clinical use. Similar results regardless of diagnosis suggest physical competence deficits are not primary determinants of active lifestyles. Research to enhance screening specificity is required.

Antibody Deficiency in Patients with Biallelic KARS1 Mutations.

Biallelic KARS1 mutations cause KARS-related diseases, a rare syndromic condition encompassing central and peripheral nervous system impairment, heart and liver disease, and deafness. KARS1 encodes the t-RNA synthase of lysine, an aminoacyl-tRNA synthetase, involved in different physiological mechanisms (such as angiogenesis, post-translational modifications, translation initiation, autophagy and mitochondrial function). Although patients with immune-hematological abnormalities have been individually described, results have not been collectively discussed and functional studies investigating how KARS1 mutations affect B cells have not been performed. Here, we describe one patient with severe developmental delay, sensoneurinal deafness, acute disseminated encephalomyelitis, hypogammaglobulinemia and recurrent infections. Pathogenic biallelic KARS1 variants (Phe291Val/ Pro499Leu) were associated with impaired B cell metabolism (decreased mitochondrial numbers and activity). All published cases of KARS-related diseases were identified. The corresponding authors and researchers involved in the diagnosis of inborn errors of immunity or genetic syndromes were contacted to obtain up-to-date clinical and immunological information. Seventeen patients with KARS-related diseases were identified. Recurrent/severe infections (9/17) and B cell abnormalities (either B cell lymphopenia [3/9], hypogammaglobulinemia [either IgG, IgA or IgM; 6/15] or impaired vaccine responses [4/7]) were frequently reported. Immunoglobulin replacement therapy was given in five patients. Full immunological assessment is warranted in these patients, who may require detailed investigation and specific supportive treatment.

Risk factors associated with prevalent vertebral fractures in Duchenne muscular dystrophy.

Patients with Duchenne muscular dystrophy (DMD) have a high fracture burden due to progressive myopathy and steroid-induced osteoporosis. This study in males with DMD showed that markers of systemic glucocorticoid exposure including shorter stature, greater bone age delay, and lower lumbar spine bone mineral density were associated with spine fragility. INTRODUCTION: Fragility  fractures are frequent in DMD. The purpose of this study was to identify clinical factors associated with prevalent vertebral fractures (VF) in boys, teens/young adults with Duchenne muscular dystrophy (DMD). METHODS: This was a cross-sectional study of males aged 4-25 years with DMD. VF were evaluated using the modified Genant semi-quantitative method on T4-L4 lateral spine radiographs. Areal bone mineral density (aBMD) was measured at the lumbar spine (LS) and used to estimate volumetric BMD (vBMD). Clinical factors were analyzed for their association with the Spinal Deformity Index (SDI, the sum of the Genant grades). RESULTS: Sixty participants were enrolled (mean age 11.5 years, range 5.4-19.5). Nineteen participants (32%) had a total of 67 VF; 23/67 VF (34%) were moderate or severe. Participants with VF were shorter (mean height Z-score ± standard deviation: - 3.1 ± 1.4 vs. - 1.8 ± 1.4, p = 0.001), had longer glucocorticoid exposure (mean duration 6.0 ± 3.3 vs. 3.9 ± 3.3 years, p = 0.027), greater bone age (BA) delay (mean BA to chronological age difference - 3.2 ± 3.4 vs. - 1.3 ± 1.2 years, p = 0.035), and lower LSaBMD Z-scores (mean - 3.0 ± 1.0 vs. - 2.2 ± 1.2, p = 0.023). There was no difference in LSvBMD Z-scores. Multivariable Poisson regression showed that every 0.1 mg/kg/day increment in average glucocorticoid daily dose was associated with a 1.4-fold SDI increase (95% confidence interval: 1.1-1.7, p = 0.013). Greater BA delay (p < 0.001), higher weight Z-score (p = 0.004), decreased height Z-score (p = 0.025), and lower LSvBMD Z-score (p = 0.025) were also associated with SDI increase. CONCLUSION: Readily measurable clinical variables were associated with prevalent VF in males with glucocorticoid-treated DMD. These variables may be useful to identify candidates for primary osteoporosis prevention after glucocorticoid initiation.

Further characterization of CEP85L-associated lissencephaly type 10: Report of a three-generation family and review of the literature.

Lissencephaly type 10 is a recently reported condition characterized by posterior predominant abnormalities in gyration with associated seizures, developmental delays or intellectual disability. We report a boy who presented at 5 years of age with epilepsy and developmental delays. His family history was notable for epilepsy in two prior generations associated with variable developmental and cognitive impact. Exome sequencing identified a novel missense variant in CEP85L [NM_001042475.2; c.196A>G, p.(Thr66Ala)] which segregated in four affected family members across three generations. Brain imaging of the proband demonstrated a posterior lissencephaly pattern with pachygyria, while other affected family members demonstrated a similar subcortical band heterotopia. This report expands the phenotypic spectrum of this rare disorder by describing a novel variant in CEP85L in a family with variable clinical and neuroimaging findings.

Routine lung volume recruitment in boys with Duchenne muscular dystrophy: a randomised clinical trial.

BACKGROUND: Impaired cough results in airway secretion retention, atelectasis and pneumonia in individuals with Duchenne muscular dystrophy (DMD). Lung volume recruitment (LVR) stacks breaths to inflate the lungs to greater volumes than spontaneous effort. LVR is recommended in DMD clinical care guidelines but is not well studied. We aimed to determine whether twice-daily LVR, compared with standard of care alone, attenuates the decline in FVC at 2 years in boys with DMD. METHODS: In this multicentre, assessor-blinded, randomised controlled trial, boys with DMD, aged 6-16 years with FVC >30% predicted, were randomised to receive conventional treatment or conventional treatment plus manual LVR twice daily for 2 years. The primary outcome was FVC % predicted at 2 years, adjusted for baseline FVC % predicted, age and ambulatory status. Secondary outcomes included change in chest wall distensibility (maximal insufflation capacity minus FVC) and peak cough flow. RESULTS: Sixty-six boys (36 in LVR group, 30 in control) were evaluated (median age (IQR): 11.5 years (9.5-13.5), median baseline FVC (IQR): 85% predicted (73-96)). Adjusted mean difference in FVC between groups at 2 years was 1.9% predicted (95% CI -6.9% to 10.7%; p=0.68) in the direction of treatment benefit. We found no differences in secondary outcomes. CONCLUSION: There was no difference in decline in FVC % predicted with use of twice-daily LVR for boys with DMD and relatively normal lung function. The burden associated with routine LVR may outweigh the benefit. Benefits of LVR to maintain lung health in boys with worse baseline lung function still need to be clarified. TRIAL REGISTRATION NUMBER: NCT01999075.

Not so Shocking: Electromyography in Pediatrics Remains Feasible and Diagnostically Useful.

BACKGROUND: Electrodiagnostic testing, including nerve conduction studies (NCS) and electromyography (EMG), assists with localizing lesions within the peripheral nervous system. NCS/EMG in children can be technically challenging and its relevance has been questioned in the era of affordable genetic testing. NCS/EMG provides information that may not be available in the examination of a young or developmentally delayed child. Our goal was to review the volume and referral sources of NCS/EMG studies and evaluate its feasibility and diagnostic yield at a pediatric tertiary care hospital. METHODS: Retrospective chart review of NCS/EMG studies done in pediatric patients at one center from 2014 to 2019. RESULTS: A total of 725 studies were performed, with a median age of 13.2 years (range 0-18 years). The annual number of studies remained constant throughout the study period. Neurologists and surgeons were the most common referral sources, but an increased number of referrals from geneticists was observed. Most (94.5%) NCS/EMG were done on awake patients, with only 5.5% of studies being terminated early due to tolerability of the patient. Of all studies, 326/725 (44%) demonstrated a neuromuscular abnormality, of which 63.5% (207/326) were acquired conditions. Mononeuropathies and polyneuropathies were the most common electrophysiologic diagnoses. DISCUSSION: Our study indicates that NCS/EMG remains a useful diagnostic tool, both for the diagnosis of acquired neuromuscular conditions but also as an adjunct for interpreting genetic results, as indicated by the recent increase in referrals from geneticists. Overall NCS/EMG is well tolerated and able to be performed without sedation in children of all ages.

Whole genome sequencing identifies pathogenic RNU4ATAC variants in a child with recurrent encephalitis, microcephaly, and normal stature.

Biallelic pathogenic variants in RNU4ATAC have been linked to microcephalic osteodysplastic primordial dwarfism type 1 (MOPD1). Although children with MOPD1 have been reported to show profound, life-limiting clinical decompensation at the time of a febrile illness, these episodes including magnetic resonance imaging (MRI) findings have not been well characterized. We present acute MRI brain findings for a 10-year-old girl with homozygous variants in RNU4ATAC (NR_023343.1) n.55G>A, who presented with two episodes of clinical decompensation associated with a febrile illness in early childhood. The pathogenic variants were identified by whole genome sequencing as RNU4ATAC is not captured in most exome products. Her MRI of the brain revealed symmetric, diffusion restriction of the deep gray nuclei that initially pointed to a mitochondrial disease or acute necrotizing encephalopathy. Her phenotype included microcephaly and profound cognitive impairment that can be seen with MOPD1. However, she did not demonstrate clinical or radiographic evidence of a spondyloepimetaphyseal dysplasia or "primordial dwarfism" that is characteristic of this disease. As such, the predominant neurological presentation of this child represents an atypical variant of RNU4ATAC-associated disease and should be a diagnostic consideration for geneticists and neurologists caring for children, particularly in the event of an acute clinical decline.

Expert recommendations and clinical considerations in the use of onasemnogene abeparvovec gene therapy for spinal muscular atrophy.

Spinal muscular atrophy (SMA) is an autosomal recessive, neurodegenerative disease caused by biallelic mutations in the survival motor neuron 1 (SMN1) gene. SMA is characterized by motor neuron degeneration, resulting in progressive muscle atrophy and weakness. Before the emergence of disease-modifying therapies, children with the most severe form of SMA would never achieve the ability to sit independently. Only 8% survived beyond 20 months of age without permanent ventilator support. One such therapy, onasemnogene abeparvovec, an adeno-associated virus-based gene replacement therapy, delivers functional human SMN through a one-time intravenous infusion. In addition to substantially improving survival, onasemnogene abeparvovec was found to increase motor milestone attainment and reduce the need for respiratory or nutritional support in many patients. This expert opinion provides recommendations and practical considerations on the patient-centered decisions to use onasemnogene abeparvovec. Recommendations include the need for patient-centered multidisciplinary care and patient selection to identify those with underlying medical conditions or active infections to reduce risks. We also describe the importance of retesting patients with elevated anti-adeno-associated virus serotype 9 antibodies. Recommendations for prednisolone tapering and monitoring for potential adverse events, including hepatotoxicity and thrombotic microangiopathy, are described. The need for caregiver education on managing day-to-day care at time of treatment and patient- and family-centered discussions on realistic expectations are also recommended. We detail the importance of following standard-of-care guidance and long-term monitoring of all children with SMA who have received one or more disease-modifying therapy using registries. We also highlight the need for presymptomatic or early symptomatic treatment of this disorder.

Pediatric Hyperacute Arterial Ischemic Stroke Pathways at Canadian Tertiary Care Hospitals.

BACKGROUND: Childhood acute arterial ischemic stroke (AIS) is diagnosed at a median of 23 hours post-symptom onset, delaying treatment. Pediatric stroke pathways can expedite diagnosis. Our goal was to understand the similarities and differences between Canadian pediatric stroke protocols with the aim of optimizing AIS management. METHODS: We contacted neurologists at all 16 Canadian pediatric hospitals regarding AIS management. Established protocols were analyzed for similarities and differences in eight domains. RESULTS: Response rate was 100%. Seven (44%) centers have an established AIS protocol and two (13%) have a protocol under development. Seven centers do not have a protocol; two redirect patients to adult neurology, five rely on a case-by-case approach for management. Analysis of the seven protocols revealed differences in: 1) IV-tPA dosage: age-dependent 0.75-0.9 mg/kg (N = 1) versus age-independent 0.9 mg/kg (N = 6), with maximum doses of 75 mg (N = 1) or 90 mg (N = 6); 2) IV-tPA lower age cut-off: 2 years (N = 5) versus 3 or 10 years (each N = 1); 3) IV-tPA exclusion criteria: PedNIHSS score <4 (N = 3), <5 (N = 1), <6 (N = 3); 4) first choice of pre-treatment neuroimaging: computed tomography (CT) (N = 3), magnetic resonance imaging (MRI) (N = 2) or either (N = 2); 5) intra-arterial tPA use (N = 3) and; 6) mechanical thrombectomy timeframe: <6 hour (N = 3), <24 hour (N = 2), unspecified (N = 2). CONCLUSIONS: Although 44% of Canadian pediatric hospitals have established AIS management pathways, several differences remain among centers. Some criteria (dosage, imaging) reflect adult AIS literature. Canadian expert consensus regarding IV-tPA and endovascular treatment should be established to standardize and implement AIS protocols across Canada.

Newborn Screening for Spinal Muscular Atrophy: Ontario Testing and Follow-up Recommendations.

BACKGROUND: Spinal muscular atrophy (SMA) is characterized by the progressive loss of motor neurons causing muscle atrophy and weakness. Nusinersen, the first effective SMA therapy was approved by Health Canada in June 2017 and has been added to the provincial formulary of all but one Canadian province. Access to this effective therapy has triggered the inclusion of SMA in an increasing number of Newborn Screening (NBS) programs. However, the range of disease-modifying SMN2 gene copy numbers encountered in survival motor neuron 1 (SMN1)-null individuals means that neither screen-positive definition nor resulting treatment decisions can be determined by SMN1 genotype alone. We outline an approach to this challenge, one that specifically addresses the case of SMA newborns with four copies of SMN2. OBJECTIVES: To develop a standardized post-referral evaluation pathway for babies with a positive SMA NBS screen result. METHODS: An SMA NBS pilot trial in Ontario using first-tier MassARRAY and second-tier multi-ligand probe amplification (MLPA) was launched in January 2020. Prior to this, Ontario pediatric neuromuscular disease and NBS experts met to review the evidence regarding the diagnosis and treatment of children with SMA as it pertained to NBS. A post-referral evaluation algorithm was developed, outlining timelines for patient retrieval and management. CONCLUSIONS: Ontario's pilot NBS program has created a standardized path to facilitate early diagnosis of SMA and initiation of treatment. The goal is to provide timely access to those SMA infants in need of therapy to optimize motor function and prolong survival.

Intrinsic peripheral nerve and root tumor and pseudotumoral lesions at a tertiary care pediatric hospital.

PURPOSE: Tumors affecting peripheral nerves in children are rare. Accurate diagnosis ensures that management is appropriate and timely. A review of intrinsic nerve tumors was completed to differentiate common peripheral nerve lesions based on clinical characteristics and investigations. METHODS: A retrospective review was conducted for children (< 18 years old) diagnosed with an intrinsic tumor affecting peripheral nerve(s) or roots at the Children's Hospital of Eastern Ontario (CHEO) from 2009 to 2019. RESULTS: We report 14 children with perineurioma (N = 6), neurofibroma (N = 4), intraneural ganglion cyst (N = 2), or lipomatosis (N = 2). Mean age of symptom onset was 8.2 years (range 0.3 to 17.3 years). Presenting symptoms included muscle weakness (7/14), painless muscle wasting (2/14), contracture (1/14), pain (1/14), or the identification of a painless mass (3/14). Nerve conduction studies (NCS) or electromyography (EMG) were performed in 11/14 patients. MRI was useful at differentiating between these pediatric nerve tumors. Biopsies were performed in nine patients with additional surgical management pursued in four patients. CONCLUSION: The rare nature of peripheral nerve tumors in children can pose diagnostic challenges. NCS/EMG are important to assist with localization, and MRI is useful to distinguish more benign tumors. Key MRI, clinical, and NCS features can in some cases guide management, potentially avoiding the need for invasive procedures.

Risk of Intracranial Hemorrhage Following Intravenous tPA (Tissue-Type Plasminogen Activator) for Acute Stroke Is Low in Children.

Background and Purpose- Data regarding the safety and efficacy of intravenous tPA (tissue-type plasminogen activator) in childhood acute arterial ischemic stroke are inadequate. The TIPS trial (Thrombolysis in Pediatric Stroke; National Institutes of Health grant R01NS065848)-a prospective safety and dose-finding trial of intravenous tPA in acute childhood stroke-was closed for lack of accrual. TIPS sites have subsequently treated children with acute stroke in accordance with established institutional protocols supporting data collection on outcomes. Methods- Data on children treated with intravenous tPA for neuroimaging-confirmed arterial ischemic stroke were collected retrospectively from 16 former TIPS sites to establish preliminary safety data. Participating sites were required to report all children who were treated with intravenous tPA to minimize reporting bias. Symptomatic intracranial hemorrhage (SICH) was defined as ECASS (European Cooperative Acute Stroke Study) II parenchymal hematoma type 2 or any intracranial hemorrhage associated with neurological deterioration within 36 following tPA administration. A Bayesian beta-binomial model for risk of SICH following intravenous tPA was fit using a prior distribution based on the risk level in young adults (1.7%); to test for robustness, the model was also fit with uninformative and conservative priors. Results- Twenty-six children (age range, 1.1-17 years; median, 14 years; 12 boys) with stroke and a median pediatric National Institutes of Health Stroke Scale score of 14 were treated with intravenous tPA within 2 to 4.5 hours (median, 3.0 hours) after stroke onset. No patient had SICH. Two children developed epistaxis. Conclusions- The estimated risk of SICH after tPA in children is 2.1% (95% highest posterior density interval, 0.0%-6.7%; mode, 0.9%). Regardless of prior assumption, there is at least a 98% chance that the risk is <15% and at least a 93% chance that the risk is <10%. These results suggest that the overall risk of SICH after intravenous tPA in children with acute arterial ischemic stroke, when given within 4.5 hours after symptom onset, is low.

Utility and practice of electrodiagnostic testing in the pediatric population: An AANEM consensus statement.

Nerve conduction studies and needle electromyography, collectively known as electrodiagnostic (EDX) studies, have been available for pediatric patients for decades, but the accessibility of this diagnostic modality and the approach to testing vary significantly depending on the physician and institution. The maturation of molecular diagnostic approaches and other diagnostic technologies such as neuromuscular ultrasound indicate that an analysis of current needs and practices for EDX studies in the pediatric population is warranted. The American Association of Neuromuscular & Electrodiagnostic Medicine convened a consensus panel to perform literature searches, share collective experiences, and develop a consensus statement. The panel found that electrodiagnostic studies continue to have high utility for the diagnosis of numerous childhood neuromuscular disorders, and that standardized approaches along with the use of high-quality reference values are important to maximize the diagnostic yield of these tests in infants, children, and adolescents.

Early infantile epileptic encephalopathy due to biallelic pathogenic variants in PIGQ: Report of seven new subjects and review of the literature.

We investigated seven children from six families to expand the phenotypic spectrum associated with an early infantile epileptic encephalopathy caused by biallelic pathogenic variants in the phosphatidylinositol glycan anchor biosynthesis class Q (PIGQ) gene. The affected children were all identified by clinical or research exome sequencing. Clinical data, including EEGs and MRIs, was comprehensively reviewed and flow cytometry and transfection experiments were performed to investigate PIGQ function. Pathogenic biallelic PIGQ variants were associated with increased mortality. Epileptic seizures, axial hypotonia, developmental delay and multiple congenital anomalies were consistently observed. Seizure onset occurred between 2.5 months and 7 months of age and varied from treatable seizures to recurrent episodes of status epilepticus. Gastrointestinal issues were common and severe, two affected individuals had midgut volvulus requiring surgical correction. Cardiac anomalies including arrythmias were observed. Flow cytometry using granulocytes and fibroblasts from affected individuals showed reduced expression of glycosylphosphatidylinositol (GPI)-anchored proteins. Transfection of wildtype PIGQ cDNA into patient fibroblasts rescued this phenotype. We expand the phenotypic spectrum of PIGQ-related disease and provide the first functional evidence in human cells of defective GPI-anchoring due to pathogenic variants in PIGQ.

Life expectancy at birth in Duchenne muscular dystrophy: a systematic review and meta-analysis.

Several studies indicate that prognosis for survival in Duchenne muscular dystrophy (DMD) has improved in recent decades. However, published evidence is inconclusive and some estimates may be obsolete due to improvements in standards of care, in particular the routine use of mechanical ventilatory support in advanced stages of the disease. In this systematic review and meta-analysis (PROSPERO identifier: CRD42019121800), we searched MEDLINE (through PubMed), CINAHL, Embase, PsycINFO, and Web of Science for studies published from inception up until December 31, 2018, reporting results of life expectancy in DMD. We pooled median survival estimates from individual studies using the median of medians, and weighted median of medians, methods. Risk of bias was established with the Newcastle-Ottawa Scale. Results were stratified by ventilatory support and risk of bias. We identified 15 publications involving 2662 patients from 12 countries from all inhabited continents except Africa. Median life expectancy without ventilatory support ranged between 14.4 and 27.0 years (pooled median: 19.0 years, 95% CI 18.0-20.9; weighted pooled median: 19.4 years, 18.2-20.1). Median life expectancy with ventilatory support, introduced in most settings in the 1990s, ranged between 21.0 and 39.6 years (pooled median: 29.9 years, 26.5-30.8; weighted pooled median: 31.8 years, 29.3-36.2). Risk of bias had little impact on pooled results. In conclusion, median life expectancy at birth in DMD seems to have improved considerably during the last decades. With current standards of care, many patients with DMD can now expect to live into their fourth decade of life.

A National Spinal Muscular Atrophy Registry for Real-World Evidence.

BACKGROUND: Spinal muscular atrophy (SMA) is a devastating rare disease that affects individuals regardless of ethnicity, gender, and age. The first-approved disease-modifying therapy for SMA, nusinursen, was approved by Health Canada, as well as by American and European regulatory agencies following positive clinical trial outcomes. The trials were conducted in a narrow pediatric population defined by age, severity, and genotype. Broad approval of therapy necessitates close follow-up of potential rare adverse events and effectiveness in the larger real-world population. METHODS: The Canadian Neuromuscular Disease Registry (CNDR) undertook an iterative multi-stakeholder process to expand the existing SMA dataset to capture items relevant to patient outcomes in a post-marketing environment. The CNDR SMA expanded registry is a longitudinal, prospective, observational study of patients with SMA in Canada designed to evaluate the safety and effectiveness of novel therapies and provide practical information unattainable in trials. RESULTS: The consensus expanded dataset includes items that address therapy effectiveness and safety and is collected in a multicenter, prospective, observational study, including SMA patients regardless of therapeutic status. The expanded dataset is aligned with global datasets to facilitate collaboration. Additionally, consensus dataset development aimed to standardize appropriate outcome measures across the network and broader Canadian community. Prospective outcome studies, data use, and analyses are independent of the funding partner. CONCLUSION: Prospective outcome data collected will provide results on safety and effectiveness in a post-therapy approval era. These data are essential to inform improvements in care and access to therapy for all SMA patients.

Family Perspectives on Visiting the Pediatric Emergency Department for Migraine: A Qualitative Study.

OBJECTIVE: The aim of this study was to explore the perspectives of families regarding their expectations and experience of visiting the emergency department (ED) for migraine. METHODS: This was a qualitative study involving the families of 25 patients aged 10 to 18 years receiving ED care for acute migraine. Following their visit, independent semistructured telephone interviews were conducted with both the patient and parent or guardian. Questions were designed to explore factors pertaining to the family's perspective regarding their visit to the ED and expectations for the ED visit. RESULTS: Families reported a variety of reasons for visiting the ED. The majority of participants reported that they were worried about their headaches. Families more commonly had expectations for treatment than they did for investigations. As compared with patients, parents more commonly reported specific expectations for investigations and less commonly expressed concerns about intravenous treatments. Expectations for treatment efficacy varied: whereas some parents expected complete pain relief, for others, lesser degrees of relief were considered satisfactory. The experience of treatment efficacy was related to willingness to receive the same treatment again. CONCLUSIONS: Given that a high frequency of families endorsed that they were worried about the headache when presenting to the ED, clinicians should strive to make a diagnosis of migraine in the ED setting and to educate families about this diagnosis. Because of divergent parent and patient perspectives, health care providers should inquire about family expectations, especially in relation to expectations for investigations and concerns surrounding intravenous interventions, and ensure that both the patient's and parent's perspectives are considered when developing a management plan for pediatric migraine.