Newborn screening for Duchenne muscular dystrophy: the perspectives of stakeholders.

Background: The rapidly evolving clinical landscape of Duchenne muscular dystrophy (DMD) is driving innovative approaches for early diagnosis through genomic newborn bloodspot screening (NBS). However, the potential impact of these programs on families and healthcare systems remains unexplored. This study assessed the perceived benefits, harms, barriers, and enablers for DMD NBS amongst primary caregivers of children with DMD and healthcare professionals (HCPs). Methods: This Australian multi-centre cross-sectional study used a mixed-methods convergent methodology. Participants completed a codeveloped questionnaire and their perceptions on the utility, model of care, and processes of DMD NBS were thematically analysed. Findings: Participants included 50 caregivers and 26 HCPs (68.5% and 53.1% response rate respectively). Most caregivers (40/50, 80%) perceived net benefits of DMD NBS and highlighted an early diagnosis as actionable knowledge, even with the current paucity of disease modifying therapies. This knowledge was valued to enable access to multidisciplinary supportive care (29/50, 58%), clinical trials (27/50, 54%), psychological support (28/50, 56%), inform reproductive planning (27/50, 54%), and facilitate financial planning based on the future needs of their child (27/50, 54%). Whilst HCPs acknowledged these opportunities, only 16/26 (61.5%) believed there were definite net benefits, with notable concerns over the psychological harms of diagnostic knowledge without a recourse to disease modifying therapeutic intervention early in life. Interpretation: Caregivers and HCPs perceived a range of potential benefits of DMD NBS. Health system readiness will be founded on developing an integrated model of care that not only supports the psychosocial and information needs of families receiving a newborn diagnosis of DMD, but also provides care and clinical surveillance for individuals for whom a diagnosis may remain uncertain. Funding: Medical Research Futures fund (GNT2017165, MRF2015965).

Loss of TBC1D2B causes a progressive neurological disorder with gingival overgrowth.

Biallelic loss-of-function variants in TBC1D2B have been reported in five subjects with cognitive impairment and seizures with or without gingival overgrowth. TBC1D2B belongs to the family of Tre2-Bub2-Cdc16 (TBC)-domain containing RAB-specific GTPase activating proteins (TBC/RABGAPs). Here, we report five new subjects with biallelic TBC1D2B variants, including two siblings, and delineate the molecular and clinical features in the ten subjects known to date. One of the newly reported subjects was compound heterozygous for the TBC1D2B variants c.2584C>T; p.(Arg862Cys) and c.2758C>T; p.(Arg920*). In subject-derived fibroblasts, TBC1D2B mRNA level was similar to control cells, while the TBC1D2B protein amount was reduced by about half. In one of two siblings with a novel c.360+1G>T splice site variant, TBC1D2B transcript analysis revealed aberrantly spliced mRNAs and a drastically reduced TBC1D2B mRNA level in leukocytes. The molecular spectrum included 12 different TBC1D2B variants: seven nonsense, three frameshifts, one splice site, and one missense variant. Out of ten subjects, three had fibrous dysplasia of the mandible, two of which were diagnosed as cherubism. Most subjects developed gingival overgrowth. Half of the subjects had developmental delay. Seizures occurred in 80% of the subjects. Six subjects showed a progressive disease with mental deterioration. Brain imaging revealed cerebral and/or cerebellar atrophy with or without lateral ventricle dilatation. The TBC1D2B disorder is a progressive neurological disease with gingival overgrowth and abnormal mandible morphology. As TBC1D2B has been shown to positively regulate autophagy, defects in autophagy and the endolysosomal system could be associated with neuronal dysfunction and the neurodegenerative disease in the affected individuals.

DHDDS and NUS1: A Converging Pathway and Common Phenotype.

BACKGROUND: Variants in dehydrodolichol diphosphate synthetase (DHDDS) and nuclear undecaprenyl pyrophosphate synthase 1 (NUS1) cause a neurodevelopmental disorder, classically with prominent epilepsy. Recent reports suggest a complex movement disorder and an overlapping phenotype has been postulated due to their combined role in dolichol synthesis. CASES: We describe three patients with heterozygous variants in DHDDS and five with variants affecting NUS1. They bear a remarkably similar phenotype of a movement disorder dominated by multifocal myoclonus. Diagnostic clues include myoclonus exacerbated by action and facial involvement, and slowly progressive or stable, gait ataxia with disproportionately impaired tandem gait. Myoclonus is confirmed with neurophysiology, including EMG of facial muscles. LITERATURE REVIEW: Ninety-eight reports of heterozygous variants in DHDDS, NUS1 and chromosome 6q22.1 structural alterations spanning NUS1, confirm the convergent phenotype of hypotonia at birth, developmental delay, multifocal myoclonus, ataxia, dystonia and later parkinsonism with or without generalized epilepsy. Other features include periodic exacerbations, stereotypies, anxiety, and dysmorphisms. Although their gene products contribute to dolichol biosynthesis, a key step in N-glycosylation, transferrin isoform profiles are typically normal. Imaging is normal or non-specific. CONCLUSIONS: Recognition of their shared phenotype may expedite diagnosis through chromosomal microarray and by including DHDDS/NUS1 in movement disorder gene panels.

Diagnosis and management of children with McArdle Syndrome (GSD V) in New South Wales.

Glycogen storage type V (GSD V-McArdle Syndrome) is a rare neuromuscular disorder characterised by severe pain early after the onset of physical activity. A recent series indicated a diagnostic delay of 29 years; hence reports of children affected by the disorder are uncommon (Lucia et al., 2021, Neuromuscul Disord, 31, 1296-1310). This paper presents eight patients with a median onset age of 5.5 years and diagnosis of 9.5 years. Six patients had episodes of rhabdomyolysis with creatine kinase elevations >50 000 IU/L. Most episodes occurred in relation to eccentric non-predicted activities rather than regular exercise. One of the patients performed a non-ischaemic forearm test. One patient was diagnosed subsequent to a skeletal muscle biopsy, and all had confirmatory molecular genetic diagnosis. Three were homozygous for the common PYGM:c.148C > T (p.Arg50*) variant. All but one patient had truncating variants. All patients were managed with structured exercise testing to help them identify 'second-wind', and plan an exercise regimen. In addition all also had an exercise test with 25 g maltodextrin which had statistically significant effect on ameliorating ratings of perceived exertion. GSD V is under-recognised in paediatric practice. Genetic testing can readily diagnose the condition. Careful identification of second-wind symptomatology during exercise with the assistance of a multi-disciplinary team, allows children to manage activities and tolerate exercise. Maltodextrin can be used for structured exercise, but excessive utilisation may lead to weight gain. Early intervention and education may improve outcomes into adult life.

CSF neopterin, quinolinic acid and kynurenine/tryptophan ratio are biomarkers of active neuroinflammation.

BACKGROUND: Defining the presence of acute and chronic brain inflammation remains a challenge to clinicians due to the heterogeneity of clinical presentations and aetiologies. However, defining the presence of neuroinflammation, and monitoring the effects of therapy is important given its reversible and potentially damaging nature. We investigated the utility of CSF metabolites in the diagnosis of primary neuroinflammatory disorders such as encephalitis and explored the potential pathogenic role of inflammation in epilepsy. METHODS: Cerebrospinal fluid (CSF) collected from 341 paediatric patients (169 males, median age 5.8 years, range 0.1-17.1) were examined. The patients were separated into a primary inflammatory disorder group (n = 90) and epilepsy group (n = 80), who were compared with three control groups including neurogenetic and structural (n = 76), neurodevelopmental disorders, psychiatric and functional neurological disorders (n = 63), and headache (n = 32). FINDINGS: There were statistically significant increases of CSF neopterin, kynurenine, quinolinic acid and kynurenine/tryptophan ratio (KYN/TRP) in the inflammation group compared to all control groups (all p < 0.0003). As biomarkers, at thresholds with 95% specificity, CSF neopterin had the best sensitivity for defining neuroinflammation (82%, CI 73-89), then quinolinic acid (57%, CI 47-67), KYN/TRP ratio (47%, CI 36-56) and kynurenine (37%, CI 28-48). CSF pleocytosis had sensitivity of 53%, CI 42-64). The area under the receiver operating characteristic curve (ROC AUC) of CSF neopterin (94.4% CI 91.0-97.7%) was superior to that of CSF pleocytosis (84.9% CI 79.5-90.4%) (p = 0.005). CSF kynurenic acid/kynurenine ratio (KYNA/KYN) was statistically decreased in the epilepsy group compared to all control groups (all p ≤ 0.0003), which was evident in most epilepsy subgroups. INTERPRETATION: Here we show that CSF neopterin, kynurenine, quinolinic acid and KYN/TRP are useful diagnostic and monitoring biomarkers of neuroinflammation. These findings provide biological insights into the role of inflammatory metabolism in neurological disorders and provide diagnostic and therapeutic opportunities for improved management of neurological diseases. FUNDING: Financial support for the study was granted by Dale NHMRC Investigator grant APP1193648, University of Sydney, Petre Foundation, Cerebral Palsy Alliance and Department of Biochemistry at the Children's Hospital at Westmead. Prof Guillemin is funded by NHMRC Investigator grant APP 1176660 and Macquarie University.

It Takes Two to Tango, Part II: Synthesis of A-Ring Functionalised Quinones Containing Two Redox-Active Centres with Antitumour Activities.

In 2021, our research group published the prominent anticancer activity achieved through the successful combination of two redox centres (ortho-quinone/para-quinone or quinone/selenium-containing triazole) through a copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. The combination of two naphthoquinoidal substrates towards a synergetic product was indicated, but not fully explored. Herein, we report the synthesis of 15 new quinone-based derivatives prepared from click chemistry reactions and their subsequent evaluation against nine cancer cell lines and the murine fibroblast line L929. Our strategy was based on the modification of the A-ring of para-naphthoquinones and subsequent conjugation with different ortho-quinoidal moieties. As anticipated, our study identified several compounds with IC50 values below 0.5 µM in tumour cell lines. Some of the compounds described here also exhibited an excellent selectivity index and low cytotoxicity on L929, the control cell line. The antitumour evaluation of the compounds separately and in their conjugated form proved that the activity is strongly enhanced in the derivatives containing two redox centres. Thus, our study confirms the efficiency of using A-ring functionalized para-quinones coupled with ortho-quinones to obtain a diverse range of two redox centre compounds with potential applications against cancer cell lines. Here as well, it literally takes two for an efficient tango!

Newborn screening for spinal muscular atrophy in Australia: a non-randomised cohort study.

BACKGROUND: In light of a new therapeutic era for spinal muscular atrophy (SMA), newborn screening has been proposed as a gateway to facilitate expedient diagnosis and access to therapeutics. However, there is paucity of evidence on health outcomes outside the homogenous populations in clinical trials to justify broader implementation of newborn screening for SMA. In this real-world study, we aimed to investigate the effectiveness of newborn screening coupled with access to disease-modifying therapeutics, as an intervention for SMA. METHODS: In this prospective, non-randomised cohort study done at Sydney Children's Hospital Network (NSW, Australia), we included children younger than 16 years with homozygous exon 7 deletions of survival motor neuron 1 gene (SMN1) mutations, non-selectively assigned to a screening group (incident population diagnosed by newborn screening) from Aug 1, 2018, to Aug 1, 2020, or a comparator group (incident population diagnosed by clinical referral) from Aug 1, 2016, to July 31, 2018. We excluded infants with compound heterozygous SMN1 mutations and those participating in ongoing and unpublished clinical trials. Effectiveness of newborn screening for SMA was compared using motor development milestone attainment defined by WHO Multicentre Growth Reference Study at 2 years post diagnosis. Secondary outcome measures included mortality and change in Hammersmith Infant Neurological Examination-2 (HINE-2) score, ventilation requirements, and enteral requirements 2 years from the time of diagnosis. FINDINGS: 34 children met the study inclusion criteria, but 33 children were included in the study population after one neonate was excluded due to participation in an ongoing unpublished clinical trial. 15 children were included in the screening group (seven [47%] male and eight [53%] female; median age 2·1 weeks [IQR 1·9-2·7]) and 18 children (nine [50%] male and nine [50%] female) were included in the comparator group (median age 47·8 weeks [13·0-99·9]). The 2-year survival rate was 93% (14 of 15 children) in the screening group and 89% (16 of 18) in the comparator group. Among survivors, 11 (79%) of 14 walked independently or with assistance in the screening group, compared with one (6%) of 16 children in the comparator group (χ2=16·27; p<0·0001). A significantly greater change in motor function was observed in the screening group compared with the comparator group over 2 years (HINE-2 score group difference, 12·32; p<0·0001). The requirement for non-intensive ventilation or feeding support at follow-up was higher in the comparator group than in the screening group (odds ratio 7·1 [95% CI 0·7-70·2]). Significant predictors of functional motor outcomes as determined by HINE-2 score at 2 years post diagnosis were HINE-2 score (p=0·0022), CHOP-INTEND (p=0·0001), compound muscle action potential (CMAP; p=0·0006), and disease status (p=0·023) at diagnosis. INTERPRETATION: Newborn screening for SMA, coupled with early access to disease-modifying therapies, effectively ameliorates the functional burden and associated comorbidities for affected children. For children diagnosed through newborn screening, motor score, CMAP, and disease status at diagnosis has clinical utility to determine functional independence. FUNDING: Brain Foundation and National Health and Medical Research Council.

Urgent computed tomography angiography in paediatric stroke.

AIM: To improve delivery of acute therapies for acute ischaemic stroke (AIS). METHOD: We identified factors influencing the speed of diagnosis and delivery of acute therapies in a prospective cohort of 21 children with suspected AIS (eight with AIS, 13 stroke mimics) and explored them in a retrospective cohort with confirmed AIS. RESULTS: Approximately half of the prospective and total AIS cohorts presented with acute, sustained hemiparesis, and were diagnosed relatively quickly. AIS was suspected and diagnosed more slowly in the half presenting with symptoms other than sustained hemiparesis. Thirty-one out of 51 patients with AIS (19 females, 32 males, mean age 8 years 6 months, SD 5 years 4 months) had arterial abnormalities identified by computed tomography angiography (CTA) or magnetic resonance angiography (MRA): 11 with large vessel occlusion, six with dissection, five with moyamoya disease, nine with other arteriopathies. Among these patients, those initially imaged with CTA were diagnosed more quickly than those with initial magnetic resonance imaging/angiography, which facilitated thrombectomy and thrombolytic therapy. Twenty out of 51 had AIS without arterial abnormalities on CTA or MRA: eight with lenticulostriate vasculopathy and 12 with other small-vessel AIS. Among these patients, 80% were ineligible for thrombolysis for reasons beyond delay to diagnosis, and all showed good outcomes with supportive treatments alone. INTERPRETATION: Clinical features at presentation influence rapidity with which childhood AIS is suspected and diagnosed. Readily available CTA can direct thrombectomy in patients with large vessel occlusion and thrombolysis in most, but not all, eligible patients. WHAT THIS PAPER ADDS: Children with acute ischaemic stroke (AIS) commonly present with symptoms other than sustained hemiparesis. Stroke is more slowly recognized in these patients, which limits potential therapies. Computed tomography angiography (CTA) accurately identifies AIS with large vessel occlusion, enabling timely endovascular thrombectomy. CTA is sufficient to direct thrombolytic therapy in most eligible children. Most childhood AIS without arterial abnormalities identified by CTA had good outcomes.

Incidence of Duchenne muscular dystrophy in the modern era; an Australian study.

Duchenne muscular dystrophy (DMD), an X-linked recessive condition is maternally inherited in two-thirds of affected boys. It is important to establish carrier status of female relatives to restore reproductive confidence for non-carriers and facilitate reproductive options and cardiac surveillance for carriers. This study investigates disease incidence within an Australian model of cascade screening and evolving genetic diagnostic technologies. A retrospective population-based cohort study of all genetically and/or histopathologically confirmed males with DMD, born in New South Wales and the Australian Capital Territory was undertaken from 2002-2012. Cases were identified using state-wide molecular laboratory and clinical databases. The annual disease incidence and "theoretically" preventable cases were extrapolated over the study period. Proband genotype/phenotype, pedigree analysis, carrier-risk and extent of cascade screening were also determined. The cumulative incidence of disease was 19.7 per 100,000 male live births and 1 in 5076 live born males were diagnosed with DMD. Differences in disease incidence were not statistically different when compared between 2002-2007 and 2008-2012 (incidence rate ratio = 1.13, 95% CI 0.76-1.69, p = 0.52). The incidence rate ratio of theoretically preventable cases did not significantly change between 2002-2007 and 2008-2012 (incidence rate ratio = 2.07, 95% CI 0.58-9.21, p = 0.23). Current diagnostic and cascade screening models have limitations in their impact on disease incidence, due to a spectrum of logistical, patient and condition related factors. Innovative approaches to reduce DMD incidence may be better achieved by preconception or early pregnancy carrier screening, prenatal exome sequencing and newborn screening.

Onasemnogene abeparvovec in spinal muscular atrophy: an Australian experience of safety and efficacy.

OBJECTIVE: To provide a greater understanding of the tolerability, safety and clinical outcomes of onasemnogene abeparvovec in real-world practice, in a broad population of infants with spinal muscular atrophy (SMA). METHODS: A prospective cohort study of children with SMA treated with onasemnogene abeparvovec at Sydney Children's Hospital Network, Australia was conducted from August 2019 to November 2021. Safety outcomes included clinical and laboratory evaluations. Efficacy assessments included World Health Organisation (WHO) motor milestones, oral and swallowing abilities, and requirements for respiratory support. The implementation of a model of care for onasemnogene abeparvovec administration in health practice is described. RESULTS: 21 children were treated (age range, 0.65-24 months; body weight range, 2.5-12.5 kg) and 19/21 (90.4%) had previous nusinersen. Transient treatment-related side effects occurred in all children; vomiting (100%), transaminitis (57%) and thrombocytopaenia (33%). Incidence of moderate/severe transaminitis was significantly greater in infants weighing ≥8 kg compared with <8 kg (p < 0.05). Duration of prednisolone following treatment was prolonged (mean 87.5 days, range 57-274 days). 16/21 (76%) children gained at least one WHO motor milestone. Stabilisation or improvement in bulbar or respiratory function was observed in 20/21 (95.2%) patients. Implementation challenges were mitigated by developing standard operating procedures and facilitating exchange of knowledge. INTERPRETATION: This study provides real-world evidence to inform treatment decisions and guide therapeutic expectations for onasemnogene abeparvovec and combination therapy for SMA in health practice, especially for children weighing ≥8 kg receiving higher vector loads. Proactive clinical and laboratory surveillance is essential to facilitate individualised management of risks.

Effect of a multicomponent nutritional supplement on functional outcomes for Duchenne muscular dystrophy: A randomized controlled trial.

BACKGROUND & AIMS: Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular condition causing progressive muscle weakness and premature death. Whilst effective treatments such as gene therapy are developed, families often seek complementary therapies such as nutrition supplements to help their son maintain function; however, there is limited evidence supporting the use of nutritional supplements in DMD. This study aimed to compare the effect of a Standard nutritional supplement with an Enhanced nutritional supplement combining three nutriceuticals on functional outcomes in ambulatory boys with Duchenne muscular dystrophy (DMD). DESIGN: A 50-week double blinded, randomized, controlled crossover trial was conducted in four Australian neuromuscular centres. Primary outcome measures were 6-min walk distance (6MWD) and community ambulation (StepWatch™ Activity Monitoring). Secondary outcome measures included body composition and quality of life. Serum 25-hydroxyvitamin D was measured. RESULTS: Twenty-seven boys completed the intervention. Traditional crossover analysis demonstrated the Enhanced supplement compared to the Standard supplement was associated with a difference of +12 (95% CI: -16, 40) metres in 6MWD, +0.5 (95% CI: -53, 54) inactive minutes per day and -95 (95% CI: -887, 696) steps per day. A mixed effect model indicated a potentially clinically important effect of the Enhanced supplement on the 6MWD of +31 (95% CI: -19, 81) metres. Mean serum 25 hydroxyvitamin D levels at week 50 was 94 (95% CI: 84, 104) nmol/L. There was no observable effect of either supplement regime on body composition or quality of life. CONCLUSIONS: Whilst a positive effect of the Enhanced supplement on functional outcomes was observed, this finding was inconclusive due to the small sample size. The results do not support the use of combined nutritional supplements to improve body composition or quality of life in DMD. A dose of 2000 IU vitamin D was an adequate dose to raise serum 25-hydroxyvitamin D over 50 weeks. CLINICAL TRIAL REGISTRY: Registry #: ACTRN12610000462088, http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12610000462088.

WGS and RNA Studies Diagnose Noncoding DMD Variants in Males With High Creatine Kinase.

OBJECTIVE: To describe the diagnostic utility of whole-genome sequencing and RNA studies in boys with suspected dystrophinopathy, for whom multiplex ligation-dependent probe amplification and exomic parallel sequencing failed to yield a genetic diagnosis, and to use remnant normal DMD splicing in 3 families to define critical levels of wild-type dystrophin bridging clinical spectrums of Duchenne to myalgia. METHODS: Exome, genome, and/or muscle RNA sequencing was performed for 7 males with elevated creatine kinase. PCR of muscle-derived complementary DNA (cDNA) studied consequences for DMD premessenger RNA (pre-mRNA) splicing. Quantitative Western blot was used to determine levels of dystrophin, relative to control muscle. RESULTS: Splice-altering intronic single nucleotide variants or structural rearrangements in DMD were identified in all 7 families. Four individuals, with abnormal splicing causing a premature stop codon and nonsense-mediated decay, expressed remnant levels of normally spliced DMD mRNA. Quantitative Western blot enabled correlation of wild-type dystrophin and clinical severity, with 0%-5% dystrophin conferring a Duchenne phenotype, 10% ± 2% a Becker phenotype, and 15% ± 2% dystrophin associated with myalgia without manifesting weakness. CONCLUSIONS: Whole-genome sequencing relied heavily on RNA studies to identify DMD splice-altering variants. Short-read RNA sequencing was regularly confounded by the effectiveness of nonsense-mediated mRNA decay and low read depth of the giant DMD mRNA. PCR of muscle cDNA provided a simple, yet informative approach. Highly relevant to genetic therapies for dystrophinopathies, our data align strongly with previous studies of mutant dystrophin in Becker muscular dystrophy, with the collective conclusion that a fractional increase in levels of normal dystrophin between 5% and 20% is clinically significant.

Diagnostic Yield of Whole Genome Sequencing After Nondiagnostic Exome Sequencing or Gene Panel in Developmental and Epileptic Encephalopathies.

OBJECTIVE: To assess the benefits and limitations of whole genome sequencing (WGS) compared to exome sequencing (ES) or multigene panel (MGP) in the molecular diagnosis of developmental and epileptic encephalopathies (DEE). METHODS: We performed WGS of 30 comprehensively phenotyped DEE patient trios that were undiagnosed after first-tier testing, including chromosomal microarray and either research ES (n = 15) or diagnostic MGP (n = 15). RESULTS: Eight diagnoses were made in the 15 individuals who received prior ES (53%): 3 individuals had complex structural variants; 5 had ES-detectable variants, which now had additional evidence for pathogenicity. Eleven diagnoses were made in the 15 MGP-negative individuals (68%); the majority (n = 10) involved genes not included in the panel, particularly in individuals with postneonatal onset of seizures and those with more complex presentations including movement disorders, dysmorphic features, or multiorgan involvement. A total of 42% of diagnoses were autosomal recessive or X-chromosome linked. CONCLUSION: WGS was able to improve diagnostic yield over ES primarily through the detection of complex structural variants (n = 3). The higher diagnostic yield was otherwise better attributed to the power of re-analysis rather than inherent advantages of the WGS platform. Additional research is required to assist in the assessment of pathogenicity of novel noncoding and complex structural variants and further improve diagnostic yield for patients with DEE and other neurogenetic disorders.

Growth and nutrition in pediatric neuromuscular disorders.

BACKGROUND & AIMS: Little is currently known about the nutrition and growth outcomes in children with neuromuscular disorders (NMDs), and these are likely disease dependent. The aim of this study was to describe the range of nutritional issues in pediatric NMDs and identify similarities and differences in growth outcomes and nutritional needs in children with a variety of NMDs at different ages, with the goal of informing future services. METHODS: In this cross-sectional study we collected data on growth, dietetic interventions and nutrition-related issues in 160 children who attended a multidisciplinary clinic in a tertiary children's hospital, from February to December 2019. Children with significant weakness affecting mobility before the age of 3 years were clinically grouped into 'early-onset NMDs'. RESULTS: Across our clinic, 42.5% children had a history of chronic gastrointestinal issues, and 34.4% received dietetic care on the day of clinical visit. Children with early-onset NMDs had significantly higher prevalence of swallowing issues, gastroesophageal reflux, and vomiting, as well as higher frequency of dietetic consultations, high energy diet, swallowing assessment and tube-feeding, compared to later-onset NMDs (p < 0.05). In total, 49.2% children with NMDs had an abnormal weight, in which the prevalence of underweight (n = 24, 19.2%) was significantly higher compared to normal Australian children (8.2%) (p < 0.05). In Duchenne muscular dystrophy, over 50% children were overweight/obese. CONCLUSION: Among children with NMDs, there were many disease-specific nutrition-related symptoms, growth issues, and dietetic practices that were tailored to individual needs. Future studies should focus on measuring the impact of specific dietetic practices on growth and nutritional outcomes, as well as developing a precision medicine approach tailored to the individual nutritional needs of children with NMDs.

Changes in grassland management and linear infrastructures associated to the decline of an endangered bird population.

European grassland birds are experiencing major population declines, mainly due to changes in farmland management. We analyzed the role of habitat availability, grazing management and linear infrastructures (roads and power lines) in explaining spatial and temporal variation in the population density of little bustards (Tetrax tetrax) in Portugal, during a decade in which the species population size halved. We used data from 51 areas (totaling ca. 1,50,000 ha) that were sampled in two different periods (2003-2006 and 2016). In 2003-2006, when the species occurred at high densities, habitat availability was the only factor affecting spatial variation in bustard density. In the 2016 survey, variation in density was explained by habitat availability and livestock management, with reduced bird numbers in areas with higher proportions of cattle. Population declines across the study period were steeper in areas that initially held higher densities of bustards and in areas with a higher proportion of cattle in the total stocking rate. Areas with higher densities of power lines also registered greater density declines, probably due to avoidance behavior and to increased mortality. Overall, our results show little bustards are currently lacking high quality grassland habitat, whose persistence depends on extensive grazing regimes and low linear infrastructure densities.

Biallelic loss-of-function variants in TBC1D2B cause a neurodevelopmental disorder with seizures and gingival overgrowth.

The family of Tre2-Bub2-Cdc16 (TBC)-domain containing GTPase activating proteins (RABGAPs) is not only known as key regulatorof RAB GTPase activity but also has GAP-independent functions. Rab GTPases are implicated in membrane trafficking pathways, such as vesicular trafficking. We report biallelic loss-of-function variants in TBC1D2B, encoding a member of the TBC/RABGAP family with yet unknown function, as the underlying cause of cognitive impairment, seizures, and/or gingival overgrowth in three individuals from unrelated families. TBC1D2B messenger RNA amount was drastically reduced, and the protein was absent in fibroblasts of two patients. In immunofluorescence analysis, ectopically expressed TBC1D2B colocalized with vesicles positive for RAB5, a small GTPase orchestrating early endocytic vesicle trafficking. In two independent TBC1D2B CRISPR/Cas9 knockout HeLa cell lines that serve as cellular model of TBC1D2B deficiency, epidermal growth factor internalization was significantly reduced compared with the parental HeLa cell line suggesting a role of TBC1D2B in early endocytosis. Serum deprivation of TBC1D2B-deficient HeLa cell lines caused a decrease in cell viability and an increase in apoptosis. Our data reveal that loss of TBC1D2B causes a neurodevelopmental disorder with gingival overgrowth, possibly by deficits in vesicle trafficking and/or cell survival.

Nutritional practices in pediatric patients with neuromuscular disorders.

Children with neuromuscular disorders (NMDs) may experience a spectrum of nutritional issues with adverse health consequences. This review summarizes the current understanding of nutritional care in pediatric NMDs, recognizing disease-specific aspects of nutrition alongside the challenges and needs in dietetic care. General or disease-related nutritional issues for children with NMDs include being underweight, overweight, or obese and having swallowing difficulty, gastroesophageal reflux, diarrhea, and/or constipation. Specific challenges in NMD nutritional assessment include alterations in body composition and energy requirements and difficulties in measuring anthropometry. Multidisciplinary dietetic intervention focuses on optimizing nutrient intakes to avert growth failure or obesity and managing feeding difficulties and gastrointestinal problems. Care guidelines are disease specific and vary in approach and detail. To promote best clinical practice across diverse settings, a standardized approach to assessing growth and nutrition across all pediatric NMDs is needed to direct optimal care centered on individual requirements. Future studies should focus on determining the prevalence of specific nutritional issues and the effectiveness of specific interventions among various pediatric NMD populations.

Endovascular clot retrieval for acute ischaemic stroke due to basilar artery occlusion in childhood.

Endovascular clot retrieval (ECR) is an emerging therapy for treatment of acute ischaemic stroke (AIS) in adults, including basilar artery occlusion (BAO). Its role in children is not well established. We report four consecutive children with AIS due to BAO treated with ECR in Sydney, Australia. We reviewed the literature to characterize the 'natural course' of AIS due to BAO in children not treated with thrombolysis or ECR, and compared their outcome with our patients and reported children with BAO treated with ECR. Despite delays in diagnosis, ECR achieved recanalization in our four children. Three children had a good outcome (Paediatric Modified Rankin Score [PedmRS] 0-2). One child with acute leukaemia suffered recurrent basilar occlusion and died of brainstem dysfunction. Literature review identified 111 children exhibiting the natural course of AIS due to BAO, among whom 42% had good outcomes (PedmRS 0-2), 48% had significant residual disability (PedmRS 3-5), and 10% died. Of 34 children treated with ECR, 28 (82%) had good outcomes (PedmRS 0-2), five (15%) had significant residual disability (PedmRS 3-5), and one (3%) died. Complications of ECR were uncommon. These observations suggest ECR may be beneficial for children with AIS due to BAO. WHAT THIS PAPER ADDS: Children with acute ischaemic stroke (AIS) due to basilar artery occlusion (BAO) experience significant morbidity and mortality. Endovascular clot retrieval may be beneficial in children with AIS due to BAO.

Next generation sequencing of human enterovirus strains from an outbreak of enterovirus A71 shows applicability to outbreak investigations.

BACKGROUND: The most recent documented Australian outbreak of enterovirus A71 (EV-A71) occurred in Sydney from 2012 to 2013. Over a four-month period more than 100 children presented to four paediatric hospitals with encephalitic presentations including fever and myoclonic jerks. The heterogeneous presentations included typical encephalomyelitis, and cardiopulmonary complications. OBJECTIVES: To characterise the genomes of enterovirus strains circulating during the 2013 Sydney EV-A71 outbreak and determine their phylogeny, phylogeography and association between genome and clinical phenotype. STUDY DESIGN: We performed an analysis of enterovirus (EV) positive specimens from children presenting to hospitals in the greater Sydney region of Australia during the 2013 outbreak. We amplified near full-length genomes of EV, and used next generation sequencing technology to sequence the virus. We used phylogenetic/phylogeographic analysis to characterize the outbreak viruses. RESULTS: We amplified and sequenced 23/63 (37 %) genomes, and identified the majority (61 %) as EV-A71. The EV-A71 sequences showed high level sequence homology to C4a genogroups of EV-A71 circulating in China and Vietnam during 2012-13. Phylogenetic analysis showed EV-A71 strains associated with more severe symptoms, including encephalitis or cardiopulmonary failure, grouped together more closely than those from patients with hand, foot and mouth disease. Amongst the non-EV-A71 sequences were five other EV subtypes (representing enterovirus subtypes A and B), reflecting the diversity of EV co-circulation within the community. CONCLUSIONS: This is the first Australian study investigating the near full-length genome of EV strains identified during a known outbreak of EV-A71. EV-A71 sequences were very similar to strains circulating in Asia during the same time period. Whole genome sequencing offers additional information over routine diagnostic testing such as characterisation of emerging recombinant strains and inform vaccine design.

Importance of muscle biopsy to establish pathogenicity of DMD missense and splice variants.

A precise genetic diagnosis of a dystrophinopathy has far-reaching implications for affected boys and their families. We present three boys with DMD single nucleotide variants associated with Becker muscular dystrophy presenting with myalgia, reduced exercise capacity, neurodevelopmental symptoms and elevated creatine kinase. The DMD variants were difficult to classify: AIII:1 a synonymous variant in exon 13 c.1602G>A, p.Lys534Lys; BIII:1 an essential splice-site variant in intron 33 c.4674+1G>A, and CII:1 a missense mutation within the cysteine-rich domain, exon 66 c.9619T>C, p.Cys3207Arg. Complementary DNA (cDNA) analysis using muscle-derived mRNA established splice-altering effects of variants for AIII:1 and BIII:1, and normal splicing in CII:1. Western blot analysis demonstrated mildly to moderately reduced dystrophin levels (17.6 - 36.1% the levels of controls), supporting dystrophinopathy as a probable diagnosis. These three cases highlight the diagnostic utility of muscle biopsy for mRNA studies and western blot to investigate DMD variants of uncertain pathogenicity, by exploring effects on splicing and dystrophin protein levels.