Immune deficiency, autoimmune disease and intellectual disability: A pleiotropic disorder caused by biallelic variants in the TPP2 gene.

Four individuals from two families presented with a multisystemic condition of suspected genetic origin that was diagnosed only after genome analysis. The main phenotypic features were immune system dysregulation (severe immunodeficiency with autoimmunity) and intellectual disability. The four individuals were found to be homozygous for a 4.4 Kb deletion removing exons 20-23 (NM_003291.4) of the TPP2 gene, predicting a frameshift with premature termination of the protein. The deletion was located on a shared chromosome 13 haplotype indicating a Swiss founder mutation. Tripeptidyl peptidase 2 (TPP2) is a protease involved in HLA/antigen complex processing and amino acid homeostasis. Biallelic variants in TPP2 have been described in 10 individuals with variable features including immune deficiency, autoimmune cytopenias, and intellectual disability or chronic sterile brain inflammation mimicking multiple sclerosis. Our observations further delineate this severe condition not yet included in the OMIM catalog. Timely recognition of TPP2 deficiency is crucial since (1) immune surveillance is needed and hematopoietic stem cell transplantation may be necessary, and (2) for provision of genetic counselling. Additionally, enzyme replacement therapy, as already established for TPP1 deficiency, might be an option in the future.

Acute monophasic erythromelalgia pain in five children diagnosed as small-fiber neuropathy.

The small-fiber polyneuropathies (SFN) are a class of diseases in which the small thin myelinated (Aδ) and/or unmyelinated (C) fibers within peripheral nerves malfunction and can degenerate. SFN usually begins in the farthest, most-vulnerable axons, so distal neuropathic pain and symptoms from microvascular dysregulation are common. It is well known in adults, e.g. from diabetes, human immunodeficiency virus, or neurotoxins, but considered extremely rare in children, linked mostly with pathogenic genetic variants in voltage-gated sodium channels. However, increasing evidence suggests that pediatric SFN is not rare, and that dysimmunity is the most common cause. Because most pediatric neurologists are unfamiliar with SFN, we report the diagnosis and management of 5 Swiss children, aged 6-11y, who presented with severe paroxysmal burning pain in the hands and feet temporarily relieved by cooling-the erythromelalgia presentation. Medical evaluations revealed autoimmune diseases in 3 families and 3/5 had preceding or concomitant infections. The standard diagnostic test (PGP9.5-immunolabeled lower-leg skin biopsy) confirmed SFN diagnoses in 3/4, and autonomic function testing (AFT) was abnormal in 2/3. Blood testing for etiology was unrevealing, including genetic testing in 3. Paracetamol and ibuprofen were ineffective. Two children responded to gabapentin plus mexiletine, one to carbamazepine, two to mexiletine plus immunotherapy (methylprednisolone/IVIg). All recovered within 6 months, remaining well for years. These monophasic tempos and therapeutic responses are most consistent with acute post-infectious immune-mediated causality akin to Guillain-Barré large-fiber polyneuropathy. Skin biopsy and AFT for SFN, neuropathic-pain medications and immunotherapy should be considered for acute sporadic pediatric erythromelalgia.

Childhood neurodegeneration associated with a specific UBTF variant: a new case report and review of the literature.

BACKGROUND: A new monogenic neurodegenerative disease affecting ribosomal metabolism has recently been identified in association with a monoallelic UBTF putative gain of function variant (NM_001076683.1:c.628G>A, hg19). Phenotype is consistent among these probands with progressive motor, cognitive, and behavioural regression in early to middle childhood. CASE PRESENTATION: We report on a child with this monoallelic UBTF variant who presented with progressive disease including regression, episodes of subacute deterioration during febrile illnesses and a remarkable EEG pattern with a transient pattern of semi-periodic slow waves. CONCLUSIONS: This case further supports the phenotype-genotype correlation of neurodegeneration associated with UBTF c.628G>A. Moreover, it brings new insights into the clinical features and EEG that could possibly serve as diagnostic markers of this otherwise nonspecific phenotype.

Comparative Study of Photoswitchable Zinc-Finger Domain and AT-Hook Motif for Light-Controlled Peptide-DNA Binding.

DNA-peptide interactions are involved in key life processes, including DNA recognition, replication, transcription, repair, organization, and modification. Development of tools that can influence DNA-peptide binding non-invasively with high spatiotemporal precision could aid in determining its role in cells and tissues. Here, the design, synthesis, and study of photocontrolled tools for sequence-specific small peptide-DNA major and minor groove interactions are reported, shedding light on DNA binding by transcriptionally active peptides. In particular, photoswitchable moieties were implemented in the peptide backbone or turn region. In each case, DNA binding was affected by photochemical isomerization, as determined in fluorescent displacement assays on model DNA strands, which provides promising tools for DNA modulation.

Feasibility, safety, and outcome of recanalization treatment in childhood stroke.

OBJECTIVE: Intravenous thrombolysis and endovascular therapy (IVT/EVT) are evidence-based treatments for adults with arterial ischemic stroke (AIS). However, randomized controlled trials in pediatric patients are lacking. This study aimed to describe feasibility, safety, and outcome of IVT/EVT in children with AIS. METHODS: This retrospective study (01/2000-12/2015) included a multicenter, population-based consecutive cohort of patients aged 1 month to 16 years, diagnosed with AIS and presenting with pediatric National Institutes of Health Stroke Scale (pedNIHSS) ≥ 4. Clinical and radiological data of patients receiving IVT/EVT were compared to those receiving standard care (SC) using linear regression to adjust for potential confounders. EVT included intra-arterial thrombolysis and/or mechanical thrombectomy. Outcome was assessed 6 months after stroke using the pediatric stroke outcome measure (PSOM). RESULTS: Overall, 150 patients (age 7.1 ± 4.9 years, 55 [37%] females) presented with pedNIHSS ≥ 4. Recanalization treatment was performed in 16 (11%), of whom 5 (3%) were treated with IVT and 11 (7%) with EVT. Patients receiving recanalization treatment were older (mean age = 11.0 vs 6.9 years, p = 0.01) and more severely affected (median pedNIHSS = 13.5 vs 8.0, p < 0.001). Death and bleeding complications did not differ between the 2 groups. Median (interquartile range) PSOM 6 months after AIS was 2.5 (1-4.3) and 1 (0-2) in the IVT/EVT and SC groups, respectively (p = 0.014). However, after multiple linear regression analysis, only higher baseline pedNIHSS remained associated with an unfavorable outcome (p < 0.001). INTERPRETATION: Recanalization treatment is feasible and seems to be safe in severely affected pediatric AIS patients. The assessment of efficacy of IVT/EVT in pediatric stroke patients requires larger studies. Ann Neurol 2018;83:1125-1132.

Incidence and outcomes of symptomatic neonatal arterial ischemic stroke.

BACKGROUND AND OBJECTIVES: Neonatal arterial ischemic stroke (NAIS) is associated with considerable lifetime burdens such as cerebral palsy, epilepsy, and cognitive impairment. Prospective epidemiologic studies that include outcome assessments are scarce. This study aimed to provide information on the epidemiology, clinical manifestations, infarct characteristics, associated clinical variables, treatment strategies, and outcomes of NAIS in a prospective, population-based cohort of Swiss children. METHODS: This prospective study evaluated the epidemiology, clinical manifestations, vascular territories, associated clinical variables, and treatment of all full-term neonates diagnosed with NAIS and born in Switzerland between 2000 and 2010. Follow-up was performed 2 years (mean 23.3 months, SD 4.3 months) after birth. RESULTS: One hundred neonates (67 boys) had a diagnosis of NAIS. The NAIS incidence in Switzerland during this time was 13 (95% confidence interval [CI], 11-17) per 100,000 live births. Seizures were the most common symptom (95%). Eighty-one percent had unilateral (80% left-sided) and 19% had bilateral lesions. Risk factors included maternal risk conditions (32%), birth complications (68%), and neonatal comorbidities (54%). Antithrombotic and antiplatelet therapy use was low (17%). No serious side effects were reported. Two years after birth, 39% were diagnosed with cerebral palsy and 31% had delayed mental performance. CONCLUSIONS: NAIS in Switzerland shows a similar incidence as other population-based studies. About one-third of patients developed cerebral palsy or showed delayed mental performance 2 years after birth, and children with normal mental performance may still develop deficits later in life.

Light and heat control over secondary structure and amyloid-like fiber formation in an overcrowded-alkene-modified Trp zipper.

The external photocontrol over peptide folding, by the incorporation of molecular photoswitches into their structure, provides a powerful tool to study biological processes. However, it is limited so far to switches that exhibit only a rather limited geometrical change upon photoisomerization and that show thermal instability of the photoisomer. Here we describe the use of an overcrowded alkene photoswitch to control a model ß-hairpin peptide. This photoresponsive unit undergoes a large conformational change and has two thermally stable isomers which has major influence on the secondary structure and the aggregation of the peptide, permitting the phototriggered formation of amyloid-like fibrils.

When should clinicians search for GLUT1 deficiency syndrome in childhood generalized epilepsies?

UNLABELLED: GLUT1 deficiency (GLUT1D) has recently been identified as an important cause of generalized epilepsies in childhood. As it is a treatable condition, it is crucial to determine which patients should be investigated. METHODS: We analyzed SLC2A1 for mutations in a group of 93 unrelated children with generalized epilepsies. Fasting lumbar puncture was performed following the identification of a mutation. We compared our results with a systematic review of 7 publications of series of patients with generalized epilepsies screened for SLC2A1 mutations. RESULTS: We found 2/93 (2.1%) patients with a SLC2A1 mutation. One, carrying a novel de novo deletion had epilepsy with myoclonic-atonic seizures (MAE), mild slowing of head growth, choreiform movements and developmental delay. The other, with a paternally inherited missense mutation, had childhood absence epilepsy with atypical EEG features and paroxysmal exercise-induced dyskinesia (PED) initially misdiagnosed as myoclonic seizures. Out of a total of 1110 screened patients with generalized epilepsies from 7 studies, 2.4% (29/1110) had GLUT1D. This rate was higher (5.6%) among 303 patients with early onset absence epilepsy (EOAE) from 4 studies. About 50% of GLUT1D patients had abnormal movements and 41% a family history of seizures, abnormal movements or both. CONCLUSION: GLUT1D is most likely to be found in MAE and in EOAE. The probability of finding GLUT1D in the classical idiopathic generalized epilepsies is very low. Pointers to GLUT1D include an increase in seizures before meals, cognitive impairment, or PED which can easily be overlooked.

Photo-controlled deactivation of immobilised lipase.

Lipase from Candida rugosa was immobilised on a quartz surface using an azobenzene-containing, bifunctional linker, which allows deactivation of the immobilised enzyme by irradiation with visible light.

Factors affecting cognitive outcome in early pediatric stroke.

OBJECTIVE: We examined cognitive performance in children after stroke to study the influence of age at stroke, seizures, lesion characteristics, neurologic impairment (NI), and functional outcome on cognitive outcome. METHODS: This was a prospectively designed study conducted in 99 children who sustained an arterial ischemic stroke (AIS) between the age of 1 month and 16 years. All children underwent cognitive and neurologic follow-up examination sessions 2 years after the insult. Cognitive development was assessed with age-appropriate instruments. RESULTS: Although mean cognitive performance was in the lower normative range, we found poorer results in subtests measuring visuoconstructive skills, short-term memory, and processing speed. Risk factors for negative cognitive outcome were young age at stroke, seizures, combined lesion location (cortical and subcortical), as well as marked NI. CONCLUSIONS: We recommend that all children with a history of AIS undergo regularly scheduled neuropsychological assessment to ensure implementation of appropriate interventions and environmental adjustments as early as possible.

A fast, visible-light-sensitive azobenzene for bioorthogonal ligation.

Azobenzenes have been used as photoresponsive units for the control of numerous biological processes. Primary prerequisites for such applications are site-selective incorporation of photoswitchable units into biomolecules and the possibility of using non-destructive and deep-tissue-penetrating visible light for the photoisomerization. Here we report a push-pull azobenzene that readily undergoes a Staudinger-Bertozzi ligation with azide groups, that can be addressed with visible light (>440 nm) and exhibits the solvato- and acidochromism typical for push-pull systems. The thermal relaxation in aqueous environment proceeds on the low-millisecond timescale, thus enabling control over biological processes on similar timescales. The approach is demonstrated in the modification of a quartz surface and in the incorporation of an azobenzene unit into a functional peptide, the third zinc finger in the mammalian factor Sp1.

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis mimicking a primary psychiatric disorder in an adolescent.

Anti-N-methyl-D-aspartate (anti-NMDA) receptor encephalitis likely has a wider clinical spectrum than previously recognized. This article reports a previously healthy 16-year-old girl who was diagnosed with anti-NMDA receptor encephalitis 3 months after onset of severe depression with psychotic features. She had no neurological manifestations, and cerebral magnetic resonance imaging (MRI) was normal. Slow background on electroencephalogram and an oligoclonal band in the cerebrospinal fluid prompted the search for anti-NMDA receptor antibodies. She markedly improved over time but remained with mild neuropsychological sequelae after a trial of late immunotherapy. Only a high index of suspicion enables recognition of the milder forms of the disease masquerading as primary psychiatric disorders.

An initial MRI picture of limbic encephalitis in subacute sclerosing panencephalitis.

BACKGROUND: Subacute sclerosing panencephalitis (SSPE) is a rare and severe long-term complication of measles. Hallmarks of this entity include progressive cognitive decline, myoclonia, a generalized periodic pattern on EEG and deep white matter abnormalities on MRI. However, imaging can be normal in early stages. AIM: We report herein the case of a previously healthy 13-years-old girl with an unusual radiological presentation. RESULTS: She presented with unilateral myoclonia, cognitive decline with memory impairment and a first brain MRI with swelling of both hippocampi mimicking limbic encephalitis. Measles antibodies were positive in CSF and the EEG showed slow periodic complexes. CONCLUSION: This unusual radiological presentation has never been described in SSPE. Relationship between virus and limbic system are discussed.

Severe childhood encephalopathy with dyskinesia and prolonged cognitive disturbances: evidence for anti-N-methyl-D-aspartate receptor encephalitis.

AIM: We report four cases of acquired severe encephalopathy with massive hyperkinesia, marked neurological and cognitive regression, sleep disturbance, prolonged mutism, and a remarkably delayed recovery (time to full recovery between 5 and 18mo) with an overall good outcome, and its association with anti-N-methyl-d-aspartate (anti-NMDA) receptor antibodies. METHOD: We reviewed the four cases retrospectively and we also reviewed the literature. RESULTS: Anti-NMDA receptor antibodies (without ovarian teratoma detected so far) were found in the two children tested in this study. INTERPRETATION: The clinical features are similar to those first reported in 1992 by Sebire et al.,(1) and rarely recognized since. Sleep disturbance was not emphasized as part of the disorder, but appears to be an important feature, whereas coma is less certain and difficult to evaluate in this setting. The combination of symptoms, evolution (mainly seizures at onset), severity, paucity of abnormal laboratory findings, very slow recovery, and difficult management justify its recognition as a specific entity. The neuropathological substrate may be anatomically close to that involved in encephalitis lethargica, in which the same target functions (sleep and movement) are affected but in reverse, with hypersomnolence and bradykinesia. This syndrome closely resembles anti-NMDA receptor encephalitis, which has been reported in adults and is often paraneoplastic.

Status epilepticus in fragile X syndrome.

Epilepsy is frequent in fragile X syndrome (FXS), the most common cause of inherited mental retardation. Status epilepticus (SE), however, seems exceptional in FXS, particularly as an initial epileptic manifestation. To our knowledge, SE was reported in only four FXS patients. We report the clinical features and electroencephalography (EEG) findings of five children with FXS, who presented with SE as their initial seizure.

Synthesis, preferred conformation, and membrane activity of medium-length peptaibiotics: tylopeptin B.

The solid-phase synthesis and full chemical characterization of the medium-length (14-amino acid residues) peptaibol with antibiotic properties of tylopeptin B, originally extracted from the fruiting body of the mushroom Tylopilus neofelleus, are described. These data are accompanied by the results on the solution-phase synthesis via the segment condensation approach of a selected, side-chain protected, analog. A solution conformational analysis, performed by the combined use of FTIR absorption, circular dichroism, and 2D-NMR (the latter technique coupled to molecular dynamics calculations), favors the conclusion that the 3D-structure of tylopeptin B is largely helical with a preference for the alpha- or the 3(10)-helix type depending upon the nature of the solvent. Helix topology and (partial) amphiphilic character are responsible for the observed membrane-modifying properties of this peptaibiotic.

Alexander disease: early presence of cerebral MRI criteria.

Alexander disease is a rare neurodegenerative disorder. Its most frequent subtype, the infantile form, is characterized by an early onset and a rapid neurological deterioration during the first months of life. Since the publication of cerebral radiological criteria in 2001, the disease has often been recognized by magnetic resonance imaging (MRI) findings. We report the case of a girl who at the age of 3 months presented with partial seizures and a normal neurological examination. MRI revealed the presence of a periventricular rim, extensive frontal white matter abnormalities, abnormalities of the basal ganglia and thalami and contrast enhancement involving optic chiasm, fornix, hypothalamus and mamillary bodies, corresponding to four of the five reported MRI criteria for Alexander disease. Additional MRI abnormalities not described so far were also observed. The diagnosis was confirmed by genetic analysis. This case illustrates that diagnostic MRI abnormalities of Alexander disease may be present at a very young age, long before the appearance of characteristic clinical signs. Early diagnosis by MRI allows prompt counselling of families.

Perceptual defense in anxiety disorders.

Prior research by MacLeod and Rutherford (1992) indicates that anxious subjects could have perceptual strategies different from nonanxious subjects. 42 verbal stimuli of six types (disease, social anxiety, panic, agoraphobia, obsessive-compulsive, and neutral) were tachistoscopically presented to three groups of subjects, aged 18 to 60 years: Panic Disorder group (n=21: 13 women and 8 men), and Obsessive-Compulsive Disorder group (n=20: 14 women and 6 men), recruited from an outpatient clinic, and a Control group (n=22: 14 women and 8 men), recruited among students and hospital staff. The times required for correct identification were generally longer for anxious subjects but quicker for stimuli specifically related to their disorder. The data could indicate a two-step perceptual strategy or two distinct ways of perceiving, usually, a generalized perceptual defense for a majority of anxiety-loaded stimuli, but also a selectively facilitated processing for stimuli specific to the disorder.