A computational approach for detecting physiological homogeneity in the midst of genetic heterogeneity.

The human genetic dissection of clinical phenotypes is complicated by genetic heterogeneity. Gene burden approaches that detect genetic signals in case-control studies are underpowered in genetically heterogeneous cohorts. We therefore developed a genome-wide computational method, network-based heterogeneity clustering (NHC), to detect physiological homogeneity in the midst of genetic heterogeneity. Simulation studies showed our method to be capable of systematically converging genes in biological proximity on the background biological interaction network, and capturing gene clusters harboring presumably deleterious variants, in an efficient and unbiased manner. We applied NHC to whole-exome sequencing data from a cohort of 122 individuals with herpes simplex encephalitis (HSE), including 13 individuals with previously published monogenic inborn errors of TLR3-dependent IFN-α/ß immunity. The top gene cluster identified by our approach successfully detected and prioritized all causal variants of five TLR3 pathway genes in the 13 previously reported individuals. This approach also suggested candidate variants of three reported genes and four candidate genes from the same pathway in another ten previously unstudied individuals. TLR3 responsiveness was impaired in dermal fibroblasts from four of the five individuals tested, suggesting that the variants detected were causal for HSE. NHC is, therefore, an effective and unbiased approach for unraveling genetic heterogeneity by detecting physiological homogeneity.

Movement disorders in patients with alternating hemiplegia: "Soft" and "stiff" at the same time.

OBJECTIVE: To assess nonparoxysmal movement disorders in ATP1A3 mutation-positive patients with alternating hemiplegia of childhood (AHC). METHODS: Twenty-eight patients underwent neurologic examination with particular focus on movement phenomenology by a specialist in movement disorders. Video recordings were reviewed by another movement disorders specialist and data were correlated with patients' characteristics. RESULTS: Ten patients were diagnosed with chorea, 16 with dystonia (nonparoxysmal), 4 with myoclonus, and 2 with ataxia. Nine patients had more than one movement disorder and 8 patients had none. The degree of movement disorder was moderate to severe in 12/28 patients. At inclusion, dystonic patients (n = 16) were older (p = 0.007) than nondystonic patients. Moreover, patients (n = 18) with dystonia or chorea, or both, had earlier disease onset (p = 0.042) and more severe neurologic impairment (p = 0.012), but this did not correlate with genotype. All patients presented with hypotonia, which was characterized as moderate or severe in 16/28. Patients with dystonia or chorea (n = 18) had more pronounced hypotonia (p = 0.011). Bradykinesia (n = 16) was associated with an early age at assessment (p < 0.01). Significant dysarthria was diagnosed in 11/25 cases. A history of acute neurologic deterioration and further regression of motor function, typically after a stressful event, was reported in 7 patients. CONCLUSIONS: Despite the relatively limited number of patients and the cross-sectional nature of the study, this detailed categorization of movement disorders in patients with AHC offers valuable insight into their precise characterization. Further longitudinal studies on this topic are needed.

Health Care Trajectories for Children With ADHD in France: Results From the QUEST Survey.

Objective: The objective of this study is to retrospectively describe the pathway toward ADHD diagnosis and treatment, and identify potential areas for improvement. Method: Parent-reported questionnaires were collected by a national sample of ADHD specialists. Results: In total, 473 complete questionnaires were analyzed. Initial onset of ADHD symptoms was reported at a mean age of 4.45 years. Mean age at diagnosis was 8.07 years, and half of the families had seen at least three health care professionals previously. Psychiatrists were most commonly consulted. A "combined" (89% boys) and inattentive (49% boys) profile was identified. Diagnosis was made 1 year later for the latter group. Two thirds of patients received pharmacological treatment. The delay in diagnosis was identified as the main source of concern for caregivers. Conclusion: The 4-year delay in diagnosis may represent a loss of opportunity. Training health care professionals in the core symptoms of ADHD may help reduce disparities and improve patient trajectory.

Effect of desipramine on patients with breathing disorders in RETT syndrome.

Objective: Rett Syndrome (RTT) is a severe neurodevelopmental condition with breathing disorders, affecting around one in 10,000 female births. Desipramine, a noradrenaline reuptake inhibitor, reduced the number of apneas in Mecp2-deficient mice, a model of RTT. We planned a phase 2 trial to test its efficacy and its safety on breathing patterns in 36 girls with RTT. Methods: The trial was a 6-month, multicenter, randomized, double-blind, placebo-controlled study registered with ClinicalTrials.gov, number NCT00990691. Girls diagnosed according to clinical examination and confirmed by genotyping were randomly assigned in a 1:1:1 ratio to receive 2-3 mg/kg Desipramine per day (high Desipramine), 1-2 mg/kg Desipramine per day (low Desipramine), or a placebo. The primary outcome was the change of apnea hypopnea index (AHI), defined by the number of apnea and hypopnea events per hour, assessed at 6 months from baseline. Intention-to-treat analysis was applied. Results: The median change in AHI from baseline to 6 months was -31 (IQR: -37 to -11) for the high Desipramine, -17.5 (IQR: -31 to 13) for the low Desipramine, and -13 (IQR:-31 to 0) for the placebo group. We did not find any significant difference in these changes between the groups (P = 0.781). A significant inverse correlation between Desipramine plasma concentration and AHI (r = -0.44; P = 0.0002) was underlined. Interpretation: This first clinical trial of desipramine did not show clinical efficacy. Although required further studies, the significant correlation between Desipramine concentrations and improvement of AHI provided additional and relevant reasons to test the noradrenergic pathway in RTT.

Postdrome symptoms in pediatric migraine: A questionnaire retrospective study by phone in 100 patients.

Background No study dedicated to postdrome symptoms of migraine attacks is available in children and adolescents. Objective To study the resolution phase of the migraine attack in children and adolescents. Methods 100 children and adolescents with ICHD-3 beta migraine without and/or with typical aura were included. Each patient, and one of her/his parents, were interviewed by phone about the postdrome phrase of their last six months' migraine attacks. They were specifically instructed to distinguish symptoms that had begun before and went on after migraine headache cessation (referred to as persistent symptoms), and symptoms whose onset was strictly after headache cessation (referred to as true postdromes). Results 91% of patients reported persistent symptoms, with a mean of 2.9 and a median of 2; asthenia, cognitive difficulties, pallor, cognitive slowing, anorexia, somnolence, and nausea were the most frequently reported. They lasted less than 12 h in 71% of patients. True postdromes were reported by 82% of patients, with a mean of 2.6 and a median of 2; thirst, somnolence, visual disturbances, food craving, paraesthesias, and ocular pain being the most frequently reported. They lasted less than 12 h in 94% of patients. Conclusions This study showed that children and adolescents with migraine had both frequent persistent symptoms and true postdromes. Both were notably different from those reported in adults.

Arithmetic Abilities in Children With Developmental Dyslexia: Performance on French ZAREKI-R Test.

A high comorbidity between reading and arithmetic disabilities has already been reported. The present study aims at identifying more precisely patterns of arithmetic performance in children with developmental dyslexia, defined with severe and specific criteria. By means of a standardized test of achievement in mathematics ( Calculation and Number Processing Assessment Battery for Children; von Aster & Dellatolas, 2006), we analyzed the arithmetic abilities of 47 French children with dyslexia attending 3rd, 4th, and 5th grade. Of them, 40% displayed arithmetic deficits, mostly with regard to number transcoding and mental calculation. Their individual profiles of performance accounted for varying strengths and weaknesses in arithmetic abilities. Our findings showed the pathway for the development of arithmetic abilities in children with dyslexia is not unique. Our study contrasts with the hypotheses suggesting the mutual exclusiveness of the phonological representation deficit and the core number module deficit.

Trigger Factors in Childhood Migraine: A Prospective Clinic-Based Study From North of France.

The objective was to study the prevalence and characterization of pediatric migraine triggers and to compare results to this retrospective study. A total of 101 pediatric patients with ICHD-II migraine with and/or without aura were instructed to prospectively complete a diary dealing with attacks triggers for a 3-month period. Each subject reported at least 1 trigger (range: 1-14) with a total number of 532 attacks and a median per subject of 3. Lack of sleep (51.4%), stress (44.6%), warm climate (41.9%), noise (32.4%), and excitation (29.7%) were the most frequently reported. The delay between trigger exposure and attack onset was between 0 and 3 hours in 67.6% of attacks. This prospective study confirmed the findings of the authors' previous study, with the exception that number of triggers was smaller, probably due to recall bias. The 4 most frequent triggers (lack of sleep, stress, hot weather, and noise) were identical in both studies.

Stability of Pediatric Migraine Subtype After a 5-year Follow-Up.

The study assessed the 5-year follow-up outcome and possible prognostic factors of migraine subtypes with onset in childhood or adolescence. A total of 343 patients meeting the International Classification of Headache Disorders (ICHD)-II criteria for migraine without aura (MO), migraine with aura (MA), or both MO+MA (ie, 1.1, 1.2) were contacted by phone and underwent structured follow-up headache interviews. Of the original sample patients, 22.7% were headache-free at follow-up, 14.1% had a transformed headache diagnosis (tension-type headache: 8.2%, chronic daily headache: 5.8%), and 63.3% still had migraine fulfilling the criteria for ICHD-II 1.1. or 1.2, but those who were still migraineurs at follow-up were older at baseline (respectively 12.93, 9.99, and 11.02 years for MO, MA and MO+MA, P = .0005). The probability of having the same migraine subtype diagnosis at baseline and at 5-year follow-up was 55.2%, 95.1%, and 31.1% for ICHD-II 1.1, 1.2, and both 1.1 and 1.2, respectively.

Assessment of Procedural Pain in Children Using Analgesia Nociception Index: A Pilot Study.

OBJECTIVES: The Analgesia Nociception Index (ANI), based on heart rate (HR) variability analysis, is known to decrease after a painful stimulus during surgery under general anesthesia in adults. It is measured continuously and noninvasively. We studied ANI response to procedural pain in a pediatric population and ANI measurement's feasibility in this context, across age. METHODS: A prospective, noninterventional pilot study was performed. All children (between 6 mo and under 18 y) undergoing muscle biopsy conducted under analgesia and light sedation were included. Medical staff was blind to the ANI monitor. HR and ANI were recorded and analyzed during 2 periods: T1 before incision and T2 after incision. Pain was assessed by the FLACC scale at T2. We observed ANI and HR variations after incision. ANI, HR, and FLACC were compared between children younger or older than 6 years. Enrollment or technical issues were reported. RESULTS: A total of 26 children were included (median age, 6 y; ranging from 6 mo to 16 y; 16 male). ANI decreased from T1 to T2. HR, ANI, or FLACC values were not different in children younger or older than 6 years. No parents or children refused to take part in the study. No technical issues was reported. DISCUSSION: In this pilot study, ANI measurement seems relevant in pediatric procedural pain, across age. Further studies are needed to confirm these results.

New spastic paraplegia phenotype associated to mutation of NFU1.

Recently an early onset lethal encephalopathy has been described in relation to mutations of NFU1, one of the genes involved in iron-sulfur cluster metabolism. We report a new NFU1 mutated patient presenting with a milder phenotype characterized by a later onset, a slowly progressive spastic paraparesis with relapsing-remitting episodes, mild cognitive impairment and a long survival. The early white matter abnormalities observed on MRI was combined with a mixed sensory-motor neuropathy in the third decade. Our case clearly suggests the importance of considering NFU1 mutation in slowly evolving leukoencephalopathy with high glycine concentration.

15q11.2 microdeletion (BP1-BP2) and developmental delay, behaviour issues, epilepsy and congenital heart disease: a series of 52 patients.

Proximal region of chromosome 15 long arm is rich in duplicons that, define five breakpoints (BP) for 15q rearrangements. 15q11.2 microdeletion between BP1 and BP2 has been previously associated with developmental delay and atypical psychological patterns. This region contains four highly-conserved and non-imprinted genes: NIPA1, NIPA2, CYFIP1, TUBGCP5. Our goal was to investigate the phenotypes associated with this microdeletion in a cohort of 52 patients. This copy number variation (CNV) was prevalent in 0.8% patients presenting with developmental delay, psychological pattern issues and/or multiple congenital malformations. This was studied by array-CGH at six different French Genetic laboratories. We collected data from 52 unrelated patients (including 3 foetuses) after excluding patients with an associated genetic alteration (known CNV, aneuploidy or known monogenic disease). Out of 52 patients, mild or moderate developmental delay was observed in 68.3%, 85.4% had speech impairment and 63.4% had psychological issues such as Attention Deficit and Hyperactivity Disorder, Autistic Spectrum Disorder or Obsessive-Compulsive Disorder. Seizures were noted in 18.7% patients and associated congenital heart disease in 17.3%. Parents were analysed for abnormalities in the region in 65.4% families. Amongst these families, 'de novo' microdeletions were observed in 18.8% and 81.2% were inherited from one of the parents. Incomplete penetrance and variable expressivity were observed amongst the patients. Our results support the hypothesis that 15q11.2 (BP1-BP2) microdeletion is associated with developmental delay, abnormal behaviour, generalized epilepsy and congenital heart disease. The later feature has been rarely described. Incomplete penetrance and variability of expression demands further assessment and studies.

Vagus nerve stimulation for drug-resistant epilepsy: a European long-term study up to 24 months in 347 children.

OBJECTIVE: To gain insight into the long-term impact of vagus nerve stimulation (with VNS Therapy) in children with drug-resistant epilepsy, we conducted the largest retrospective multicenter study to date over an extended follow-up period of up to 24 months. METHODS: The primary objective was to assess change in seizure frequency of the predominant seizure type (defined as the most disabling seizure) following VNS device implantation. Treating physicians collected data from patient records from baseline to 6, 12, and 24 months of follow-up. RESULTS: The analysis population included 347 children (aged 6 months to 17.9 years at the time of implant). At 6, 12, and 24 months after implantation, 32.5%, 37.6%, and 43.8%, respectively, of patients had ≥ 50% reduction in baseline seizure frequency of the predominant seizure type. The responder rate was higher in a subgroup of patients who had no change in antiepileptic drugs (AEDs) during the study. Favorable results were also evident for all secondary outcome measures including changes in seizure duration, ictal severity, postictal severity, quality of life, clinical global impression of improvement, and safety. Post hoc analyses demonstrated a statistically significant correlation between VNS total charge delivered per day and an increase in response rate. VNS Therapy is indicated as adjunctive therapy in children with focal, structural epilepsies, who for any reason are not good candidates for surgical treatment following the trial of two or more AEDs. Children with predominantly generalized seizures from genetic, structural epilepsies, like Dravet syndrome or Lennox-Gastaut syndrome, could also benefit from VNS Therapy. SIGNIFICANCE: The results demonstrate that adjunctive VNS Therapy in children with drug-resistant epilepsy reduces seizure frequency and is well tolerated over a 2-year follow-up period. No new safety issues were identified. A post hoc analysis revealed a dose-response correlation for VNS in patients with epilepsy.

Further delineation of eye manifestations in homozygous 15q13.3 microdeletions including TRPM1: a differential diagnosis of ceroid lipofuscinosis.

The 15q13.3 heterozygous microdeletion is a fairly common microdeletion syndrome with marked clinical variability and incomplete penetrance. The average size of the deletion, which comprises six genes including CHRNA7, is 1.5 Mb. CHRNA7 has been identified as the gene responsible for the neurological phenotype in this microdeletion syndrome. Only seven patients with a homozygous microdeletion that includes at least CHRNA7, and is inherited from both parents have been described in the literature. The aim of this study was to further describe the distinctive eye manifestations from the analysis in the three French patients diagnosed with the classical 1.5 Mb homozygous microdeletion. Patients' ages ranged from 30 months to 9 years, and included one sib pair. They all displayed a remarkably severe identifiable clinical phenotype that included congenital blindness and convulsive encephalopathy with inconstant abnormal movements. The ophthalmological examination revealed a lack of eye tracking, optic nerve pallor, an immature response with increased latencies with no response to the checkerboard stimulations at the visual evoked potential examination, and a distinctive retina dystrophy with a negative electroretinogram in which the "b" wave was smaller than the "a" wave after a dark adapted pupil and bright flash in all patients. Clear genotype-phenotype correlations emerged, showing that this eye phenotype was secondary to homozygous deletion of TRPM1, the gene responsible for autosomal recessive congenital stationary night blindness. The main differential diagnosis is ceroid lipofuscinosis.

Clinically severe Epstein-Barr virus encephalitis with mild cerebrospinal fluid abnormalities in an immunocompetent adolescent: a case report.

A 15-year-old boy developed Epstein-Barr virus (EBV) encephalitis, a rare complication of infectious mononucleosis. The severe clinical picture and the marked neuroimaging changes were in contrast with mild cerebrospinal fluid abnormalities: leukocyte count was normal and protein level was only slightly elevated. EBV DNA was detected in cerebrospinal fluid by polymerase chain reaction.

Psychiatric and cognitive phenotype of childhood myotonic dystrophy type 1.

AIM: To investigate the psychiatric and cognitive phenotype in young individuals with the childhood form of myotonic dystrophy type 1 (DM1). METHOD: Twenty-eight individuals (15 females, 13 males) with childhood DM1 (mean age 17y, SD 4.6, range 7-24y) were assessed using standardized instruments and cognitive testing of general intelligence, visual attention, and visual-spatial construction abilities. RESULTS: Nineteen patients had repeated a school grade. The mean (SD) Full-scale IQ was 73.6 (17.5) and mean Verbal IQ was significantly higher than the mean Performance IQ: 80.2 (19.22) versus 72.95 (15.58), p=0.01. Fifteen patients had one or more diagnoses on the DSM-IV axis 1, including internalizing disorders (phobia, n=7; mood disorder, n=6; other anxiety disorders, n=5) and attention-deficit-hyperactivity disorder, inattentive subtype (n=8). Twelve out of 22 patients had alexithymia (inability to express feelings with words and to recognize and share emotional states). Cognitive testing found severe impairments in visual attention and visual-spatial construction abilities in four out of 18, and 14 out of 24 patients respectively. No diagnosis was correlated with the transmitting parent's sex or with cytosine-thymine-guanine (CTG) repeat numbers. Patients with severe visual-spatial construction disabilities had a significantly longer CTG expansion size than those with normal visual-spatial abilities (p=0.04). INTERPRETATION: Children and adolescents with childhood DM1 have frequent diagnoses on DSM-IV axis 1, with internalizing disorders being the most common type of disorder. They also have borderline low intelligence and frequent impairments in attention and visual-spatial construction abilities.

De novo microdeletions of chromosome 6q14.1-q14.3 and 6q12.1-q14.1 in two patients with intellectual disability - further delineation of the 6q14 microdeletion syndrome and review of the literature.

Interstitial 6q deletions can cause a variable phenotype depending on the size and location of the deletion. 6q14 deletions have been associated with intellectual disability and a distinct pattern of minor anomalies, including upslanted palpebral fissures with epicanthal folds, a short nose with broad nasal tip, anteverted nares, long philtrum, and thin upper lip. In this study we describe two patients with overlapping 6q14 deletions presenting with developmental delay and characteristic dysmorphism. Molecular karyotyping using array CGH analysis revealed a de novo 8.9 Mb deletion at 6q14.1-q14.3 and a de novo 11.3 Mb deletion at 6q12.1-6q14.1, respectively. We provide a review of the clinical features of twelve other patients with 6q14 deletions detected by array CGH analysis. By assessing all reported data we could not identify a single common region of deletion. Possible candidate genes in 6q14 for intellectual disability might be FILIP1, MYO6, HTR1B, and SNX14.

A patient with myoclonic epilepsy in infancy followed by myoclonic astatic epilepsy.

Myoclonic epilepsy in infancy (MEI) is a primary generalized epilepsy. According to the literature, the outcome of MEI is usually benign. Here we report a patient who developed myoclonic astatic epilepsy at age four, having been seizure free without antiepileptic drug treatment for 2 years after his recovery from MEI. At age four, a video-EEG-recording showed frequent head nodding (atonic seizures) and myoclonic astatic seizures associated with diffuse spikes or polyspikes and waves. The interictal EEG revealed frequent bursts of generalized 100-200 µV, 2-4 Hz spike-and-slow-wave complexes. Despite a general favorable outcome, more severe epilepsy syndromes may develop after MEI, and mental retardation is sometimes observed. Our case and the previous literature suggest that epilepsies following on from MEI often involve myoclonic seizures.

Brain regional glucose uptake changes in isolated cerebellar cortical dysplasia: qualitative assessment using coregistrated FDG-PET/MRI.

We aimed to assess brain regional glucose uptake (rGlcU) changes in children with isolated cerebellar cortical dysplasia (CCD) using 18-fluoro-deoxy-glucose positron emission tomography (FDG-PET). Six children aged 9 months to 11 years at the time of diagnosis, carrying isolated CCD (with no other associated posterior fossa or supratentorial malformation) underwent a brain FDG-PET and a subsequent 3DT1-weighted MRI for coregistration. The MRIs acquired previously at the time of diagnosis were reviewed to record the cerebellar dysplastic features and classify the patients as having minor, moderate, or severe CCD. The individual rGlcU was assessed qualitatively on coregistrated FDG maps. Clinical data from birth, including neurological and neuropsychological (verbal and motor skills) disturbances, were recorded. We found rGlcU changes within the cerebellum of four patients matching with the location and extent of structural abnormalities: hypometabolism in three patients with severe CCD involving the vermis and both cerebellar hemispheres and focal hypermetabolism in one patient with moderate CCD associated with a nodular heterotopic gray matter. No obvious rGlcU changes were found in the two patients with minor CCD involving the vermis only. Supratentorial rGlcU changes found commonly involved the basal ganglia bilaterally. Coregistrated FDG-PET/MRI technique is useful in detecting cerebellar cell dysfunction associated with isolated CCD. Our results enhance the need for multimodal and quantitative studies to better evaluate local and remote functional disturbances caused by CCD.