Advantages and pitfalls of an extended gene panel for investigating complex neurometabolic phenotypes

Neurometabolic disorders are markedly heterogeneous, both clinically and genetically, and are characterized by variable neurological dysfunction accompanied by suggestive neuroimaging or biochemical abnormalities. Despite early specialist input, delays in diagnosis and appropriate treatment initiation are common. Next-generation sequencing approaches still have limitations but are already enabling earlier and more efficient diagnoses in these patients. We designed a gene panel targeting 614 genes causing inborn errors of metabolism and tested its diagnostic efficacy in a paediatric cohort of 30 undiagnosed patients presenting with variable neurometabolic phenotypes. Genetic defects that could, at least partially, explain observed phenotypes were identified in 53% of cases. Where biochemical abnormalities pointing towards a particular gene defect were present, our panel identified diagnoses in 89% of patients. Phenotypes attributable to defects in more than one gene were seen in 13% of cases. The ability of in silico tools, including structure-guided prediction programmes to characterize novel missense variants were also interrogated. Our study expands the genetic, clinical and biochemical phenotypes of well-characterized (POMGNT1, TPP1) and recently identified disorders (PGAP2, ACSF3, SERAC1, AFG3L2, DPYS). Overall, our panel was accurate and efficient, demonstrating good potential for applying similar approaches to clinically and biochemically diverse neurometabolic disease cohorts

Assessing feasibility of routine identification tools for mental health disorder in neurology clinics

Objective We aimed to test the feasibility of using an online parent-completed diagnostic assessment for detecting common mental health disorders in children attending neurology clinics. The assessment does not require intervention by a mental health professional or additional time in the clinic appointment. Setting Two parallel and related screening studies were undertaken: Study 1: Tertiary paediatric neurology clinics Study 2: Secondary and tertiary paediatric neurology clinics Patients Study 1: 406 Young people aged 7-18 attending paediatric neurology clinics Study 2: 225 Young people aged 3-18 attending paediatric epilepsy clinics Interventions Parents completed online versions of the Strengths and Difficulties Questionnaire (SDQ) and Development and Wellbeing Assessment (DAWBA). Main outcome measures We investigated: the willingness of families to complete the measures, proportion identified as having mental health disorders, time taken to complete the measures and acceptability to families and clinicians. Results The mean total difficulties score of those that had completed the SDQ fell in the ‘high’ and ‘very high’ ranges. 60% and 70% of the DAWBAS completed met criteria for at least one DSM-IV disorder in study 1 and 2 respectively. 98% of the parents reported that the screening methods used were acceptable. Conclusions: Use of an online, automated screening process is a feasible method of detecting mental health disorders in children with chronic illnesses whilst minimising burden on families and clinicians. The process was highly acceptable to families who completed the full screening process and could provide a viable option of integrating mental health assessment into routine paediatric care

Diagnostic algorithm for children presenting with epilepsia partialis continua

Objective: To characterize a cohort of children with epilepsia partialis continua (EPC) and develop a diagnostic algorithm incorporating key differential diagnoses. / Methods: Children presenting with EPC to a tertiary pediatric neurology center between 2002 and 2019 were characterized. / Results: Fifty‐four children fulfilled EPC criteria. Median age at onset was 7 years (range 0.6‐15), with median follow‐up of 4.3 years (range 0.2‐16). The diagnosis was Rasmussen encephalitis (RE) in 30 of 54 (56%), a mitochondrial disorder in 12 of 54 (22.2%), and magnetic resonance imaging (MRI) lesion‐positive focal epilepsy in 6 of 54 (11.1%). No diagnosis was made in 5 of 54 (9%). Children with mitochondrial disorders developed EPC earlier; each additional year at presentation reduced the odds of a mitochondrial diagnosis by 26% (P = .02). Preceding developmental concerns (odds ratio [OR] 22, P < .001), no seizures prior to EPC (OR 22, P < .001), bilateral slowing on electroencephalogram (EEG) (OR 26, P < .001), and increased cerebrospinal fluid (CSF) protein level (OR 16) predicted a mitochondrial disorder. Asymmetry or hemiatrophy was evident on MRI at presentation with EPC in 18 of 30 (60%) children with RE, and in the remainder at a median of 6 months (range 3‐15) after EPC onset. The first diagnostic test is brain MRI. Hemiatrophy may permit a diagnosis of RE with unilateral clinical and EEG findings. For children in whom a diagnosis of RE cannot be made on first scan but the clinical and radiological presentation resembles RE, repeat imaging every 6 months is recommended to detect progressive unicortical hemiatrophy, and brain biopsy should be considered. Evidence of intrathecal inflammation (oligoclonal bands and raised neopterin) can be supportive. In children with bihemispheric EPC, rapid polymerase gamma testing is recommended and if negative, sequencing mtDNA and whole‐exome sequencing on blood‐derived DNA should be performed. / Significance: Children presenting with EPC due to a mitochondrial disorder show clinical features distinguishing them from RE and structural epilepsies. A diagnostic algorithm for children with EPC will allow targeted investigation and timely diagnosis

Notch2 and Notch3 Function Together to Regulate Vascular Smooth Muscle Development

Notch signaling has been implicated in the regulation of smooth muscle differentiation, but the precise role of Notch receptors is ill defined. Although Notch3 receptor expression is high in smooth muscle, Notch3 mutant mice are viable and display only mild defects in vascular patterning and smooth muscle differentiation. Notch2 is also expressed in smooth muscle and Notch2 mutant mice show cardiovascular abnormalities indicative of smooth muscle defects. Together, these findings infer that Notch2 and Notch3 act together to govern vascular development and smooth muscle differentiation. To address this hypothesis, we characterized the phenotype of mice with a combined deficiency in Notch2 and Notch3. Our results show that when Notch2 and Notch3 genes are simultaneously disrupted, mice die in utero at mid-gestation due to severe vascular abnormalities. Assembly of the vascular network occurs normally as assessed by Pecam1 expression, however smooth muscle cells surrounding the vessels are grossly deficient leading to vascular collapse. In vitro analysis show that both Notch2 and Notch3 robustly activate smooth muscle differentiation genes, and Notch3, but not Notch2 is a target of Notch signaling. These data highlight the combined actions of the Notch receptors in the regulation of vascular development, and suggest that while these receptors exhibit compensatory roles in smooth muscle, their functions are not entirely overlapping

Trends in pediatric epilepsy surgery in Europe between 2008 and 2015: Country‐, center‐, and age‐specific variation

OBJECTIVE: To profile European trends in pediatric epilepsy surgery (<16 years of age) between 2008 and 2015. METHODS: We collected information on volumes and types of surgery, pathology, and seizure outcome from 20 recognized epilepsy surgery reference centers in 10 European countries. RESULTS: We analyzed retrospective aggregate data on 1859 operations. The proportion of surgeries significantly increased over time (P < .0001). Engel class I outcome was achieved in 69.3% of children, with no significant improvement between 2008 and 2015. The proportion of histopathological findings consistent with glial scars significantly increased between the ages of 7 and 16 years (P for trend = .0033), whereas that of the remaining pathologies did not vary across ages. A significant increase in unilobar extratemporal surgeries (P for trend = .0047) and a significant decrease in unilobar temporal surgeries (P for trend = .0030) were observed between 2008 and 2015. Conversely, the proportion of multilobar surgeries and unrevealing magnetic resonance imaging cases remained unchanged. Invasive investigations significantly increased, especially stereo‐electroencephalography. We found different trends comparing centers starting their activity in the 1990s to those whose programs were developed in the past decade. Multivariate analysis revealed a significant variability of the proportion of the different pathologies and surgical approaches across countries, centers, and age groups between 2008 and 2015. SIGNIFICANCE: Between 2008 and 2015, we observed a significant increase in the volume of pediatric epilepsy surgeries, stability in the proportion of Engel class I outcomes, and a modest increment in complexity of the procedures

Epilepsy due to PNPO mutations: genotype, environment and treatment affect presentation and outcome.

The first described patients with pyridox(am)ine 5'-phosphate oxidase deficiency all had neonatal onset seizures that did not respond to treatment with pyridoxine but responded to treatment with pyridoxal 5'-phosphate. Our data suggest, however, that the clinical spectrum of pyridox(am)ine 5'-phosphate oxidase deficiency is much broader than has been reported in the literature. Sequencing of the PNPO gene was undertaken for a cohort of 82 individuals who had shown a reduction in frequency and severity of seizures in response to pyridoxine or pyridoxal 5'-phosphate. Novel sequence changes were studied using a new cell-free expression system and a mass spectrometry-based assay for pyridoxamine phosphate oxidase. Three groups of patients with PNPO mutations that had reduced enzyme activity were identified: (i) patients with neonatal onset seizures responding to pyridoxal 5'-phosphate (n = 6); (ii) a patient with infantile spasms (onset 5 months) responsive to pyridoxal 5'-phosphate (n = 1); and (iii) patients with seizures starting under 3 months of age responding to pyridoxine (n = 8). Data suggest that certain genotypes (R225H/C and D33V) are more likely to result in seizures that to respond to treatment with pyridoxine. Other mutations seem to be associated with infertility, miscarriage and prematurity. However, the situation is clearly complex with the same combination of mutations being seen in patients who responded and did not respond to pyridoxine. It is possible that pyridoxine responsiveness in PNPO deficiency is affected by prematurity and age at the time of the therapeutic trial. Other additional factors that are likely to influence treatment response and outcome include riboflavin status and how well the foetus has been supplied with vitamin B6 by the mother. For some patients there was a worsening of symptoms on changing from pyridoxine to pyridoxal 5'-phosphate. Many of the mutations in PNPO affected residues involved in binding flavin mononucleotide or pyridoxal 5'-phosphate and many of them showed residual enzyme activity. One sequence change (R116Q), predicted to affect flavin mononucleotide binding and binding of the two PNPO dimers, and with high residual activity was found in Groups (ii) and (iii). This sequence change has been reported in the 1000 Genomes project suggesting it could be a polymorphism but alternatively it could be a common mutation, perhaps responsible for the susceptibility locus for genetic generalized epilepsy on 17q21.32 (close to rs72823592). We believe the reduction in PNPO activity and B6-responsive epilepsy in the patients reported here indicates that it contributes to the pathogenesis of epilepsy

Clinical effectiveness of the psychological therapy Mental Health Intervention for Children with Epilepsy in addition to usual care compared with assessment-enhanced usual care alone: a multicentre, randomised controlled clinical trial in the UK

Background Mental health difficulties are common in children and young people with chronic health conditions, but many of those in need do not access evidence-based psychological treatments. The study aim was to evaluate the clinical effectiveness of integrated mental health treatment for children and young people with epilepsy, a common chronic health condition known to be associated with a particularly high rate of co-occurring mental health difficulties. Methods We conducted a parallel group, multicentre, open-label, randomised controlled trial of participants aged 3–18 years, attending epilepsy clinics across England and Northern Ireland who met diagnostic criteria for a common mental health disorder. Participants were randomised (1:1; using an independent web-based system) to receive the Mental Health Intervention for Children with Epilepsy (MICE) in addition to usual care, or assessment-enhanced usual care alone (control). Children and young people in both groups received a full diagnostic mental health assessment. MICE was a modular psychological intervention designed to treat common mental health conditions in children and young people using evidence-based approaches such as cognitive behaviour therapy and behavioural parenting strategies. Usual care for mental health disorders varied by site but typically included referral to appropriate services. Participants, along with their caregivers, and clinicians were not masked to treatment allocation but statisticians were masked until the point of analysis. The primary outcome, analysed by modified intention-to-treat, was the parent-report Strengths and Difficulties Questionnaire (SDQ) at 6 months post-randomisation. The study is complete and registered with ISRCTN (57823197). Findings 1401 young people were potentially deemed eligible for study inclusion. Following the exclusion of 531 young people, 870 participants were assessed for eligibility and completed the SDQ, and 480 caregivers provided consent for study inclusion between May 20, 2019, and Jan 31, 2022. Between Aug 28, 2019, and Feb 21, 2022, 334 participants (mean ages 10·5 years [SD 3·6] in the MICE group vs 10·3 [4·0] in control group at baseline) were randomly assigned to an intervention using minimisation balanced by age, primary mental health disorder, diagnosis of intellectual disability, and autistic spectrum disorder at baseline. 168 (50%) of the participants were female and 166 (50%) were male. 166 participants were randomly assigned to the MICE group and 168 were randomly assigned to the control group. At 6 months, the mean SDQ difficulties for the 148 participants in the MICE group was 17·6 (SD 6·3) and 19·6 (6·1) for the 148 participants in the control group. The adjusted effect of MICE was –1·7 (95% CI –2·8 to –0·5; p=0·0040; Cohen's d, 0·3). 14 (8%) patients in the MICE group experienced at least one serious adverse event compared with 24 (14%) in the control group. 68% percent of serious adverse events (50 events) were admission due to seizures. Interpretation MICE was superior to assessment-enhanced usual care in improving symptoms of emotional and behavioural difficulties in young people with epilepsy and common mental health disorders. The trial therefore shows that mental health comorbidities can be effectively and safely treated by a variety of clinicians, utilising an integrated intervention across ages and in the context of intellectual disability and autism. The evidence from this trial suggests that such a model should be fully embedded in epilepsy services and serves as a model for other chronic health conditions in young people