Delineating the neurological phenotype in children with defects in the ECHS1 or HIBCH gene.

The neurological phenotype of 3-hydroxyisobutyryl-CoA hydrolase (HIBCH) and short-chain enoyl-CoA hydratase (SCEH) defects is expanding and natural history studies are necessary to improve clinical management. From 42 patients with Leigh syndrome studied by massive parallel sequencing, we identified five patients with SCEH and HIBCH deficiency. Fourteen additional patients were recruited through collaborations with other centres. In total, we analysed the neurological features and mutation spectrum in 19 new SCEH/HIBCH patients. For natural history studies and phenotype to genotype associations we also included 70 previously reported patients. The 19 newly identified cases presented with Leigh syndrome (SCEH, n = 11; HIBCH, n = 6) and paroxysmal dystonia (SCEH, n = 2). Basal ganglia lesions (18 patients) were associated with small cysts in the putamen/pallidum in half of the cases, a characteristic hallmark for diagnosis. Eighteen pathogenic variants were identified, 11 were novel. Among all 89 cases, we observed a longer survival in HIBCH compared to SCEH patients, and in HIBCH patients carrying homozygous mutations on the protein surface compared to those with variants inside/near the catalytic region. The SCEH p.(Ala173Val) change was associated with a milder form of paroxysmal dystonia triggered by increased energy demands. In a child harbouring SCEH p.(Ala173Val) and the novel p.(Leu123Phe) change, an 83.6% reduction of the protein was observed in fibroblasts. The SCEH and HIBCH defects in the catabolic valine pathway were a frequent cause of Leigh syndrome in our cohort. We identified phenotype and genotype associations that may help predict outcome and improve clinical management.

Respuesta clínica y neurofisiológica a la efedrina en un paciente con síndrome miasténico congénito de canal lento / Clinical and neurophysiological response to ephedrine in a patient affected with slow-channel congenital myasthenic syndrome

INTRODUCCIÓN: El síndrome miasténico congénito de canal lento, o síndrome de canales lentos, es un trastorno neuromuscular progresivo hereditario, autosómico dominante, causado por una activación anormal de los receptores de la acetilcolina en la unión neuromuscular. La alteración histopatológica característica es la degeneración selectiva de la placa terminal y la membrana postsináptica debido a la sobrecarga de calcio. La piridostigmina debe evitarse en este síndrome, y la quinidina o la fluoxetina son las terapias recomendadas actualmente. CASO CLÍNICO: Niña de 11 años con un fenotipo de cinturas de síndrome miasténico congénito de canal lento que presenta debilidad y fatiga lentamente progresivas desde los 8 años. Tras un empeoramiento clínico con piridostigmina, iniciado empíricamente antes de que los resultados de la secuenciación del exoma estuvieran disponibles, se observó una respuesta espectacular y sostenida con efedrina en monoterapia. La secuenciación del exoma reveló una mutación heterocigota de novo en el gen CHRNB1: c.865G>A; p.Val289Met (NM_000747.2). El estudio electromiográfico con estimulación repetitiva en el nervio peroneo mostró una disminución anormal en la amplitud (23,9%) y también la génesis de un segundo potencial de acción muscular compuesto más pequeño después del pico de la onda M principal en los nervios motores mediano, cubital y peroneo. CONCLUSIÓN: Aunque se han documentado respuestas favorables a agonistas adrenérgicos en asociación con la fluoxetina, ésta representa la primera aportación que documenta una respuesta clínica relevante con efedrina en monoterapia en un paciente con síndrome miasténico congénito de canal lento. Los agonistas adrenérgicos pueden considerarse una opción terapéutica en pacientes con este síndrome

INTRODUCTION: Slow-channel congenital myasthenic syndrome is an autosomal dominant inherited progressive neuromuscular disorder caused by abnormal gating of mutant acetylcholine receptors in the neuromuscular junction. Its pathological hallmark is selective degeneration of the endplate and postsynaptic membrane due to calcium overload. Pyridostigmine should be avoided in this syndrome, being quinidine or fluoxetine the current recommended therapies. CASE REPORT: An 11-year-old girl with a limb-girdle phenotype of slow-channel congenital myasthenic syndrome presenting with a slowly progressive fatigable weakness at the age of 8 years. After a clinical worsening with pyridostigmine, empirically started before the exome sequencing results were available, a dramatic and sustained response to ephedrine monotherapy was observed. Whole exome sequencing revealed a de novo heterozygous mutation in CHRNB1 gene: c.865G>A; p.Val289Met (NM_000747.2). An abnormal decrement in amplitude (23.9%) from the first to fifth intravollley waveform was revealed after repetitive peroneal nerve stimulation at low frequencies. In addition, a second smaller compound muscle action potential after the peak of the main M-wave in median, ulnar and peroneal motor nerves was observed. CONCLUSION: Favorable responses to adrenergic agonists added to fluoxetine had been reported. However, to the best of our knowledge this is the first report on effective monotherapy with ephedrine in a slow-channel congenital myasthenic syndrome patient. Adrenergic agonists may be considered as a therapeutic option in patients with this syndrome

Copy number variation analysis of patients with intellectual disability from North-West Spain.

Intellectual disability (ID) is a complex and phenotypically heterogeneous neurodevelopmental disorder characterized by significant deficits in cognitive and adaptive skills, debuting during the developmental period. In the last decade, microarray-based copy number variation (CNV) analysis has been proved as a strategy particularly useful in the discovery of loci and candidate genes associated with these phenotypes and is widely used in the clinics with a diagnostic purpose. In this study, we evaluated the usefulness of two genome-wide high density SNP microarrays -Cytogenetics Whole-Genome 2.7M SNP array (n=126 patients; Group 1) and CytoScan High-Density SNP array (n=447 patients; Group 2)- in the detection of clinically relevant CNVs in a cohort of ID patients from Galicia (NW Spain). In 159 (27.7%) patients, we detected 186 rare exonic chromosomal imbalances, that were grouped into the following classes: Clinically relevant (67/186; 36.0%), of unknown clinical significance (93/186; 50.0%) and benign (26/186; 14.0%). The 67 pathogenic CNVs were identified in 64 patients, which means an overall diagnostic yield of 11.2%. Overall, we confirmed that ID is a genetically heterogeneous condition and emphasized the importance of using genome-wide high density SNP microarrays in the detection of its genetic causes. Additionally, we provided clinical and molecular data of patients with pathogenic or likely pathogenic CNVs and discussed the potential implication in neurodevelopmental disorders of genes located within these variants.

Caracterización molecular y descripción fenotípica de dos casos con aberraciones cromosómicas recíprocas en la región de los síndromes de microdeleción/microduplicación 3q29 / Molecular characterisation and phenotypic description of two patients with reciprocal chromosomal aberrations in the region of the 3q29 microdeletion/microduplication syndromes

Introducción. Los síndromes de microdeleción y microduplicación 3q29 se caracterizan por una marcada heterogeneidad fenotípica, y el retraso del desarrollo y la discapacidad intelectual de grado leve-moderado son las manifestaciones clínicas más frecuentes. Casos clínicos. Dos pacientes con aberraciones cromosómicas recíprocas en la región 3q29. La paciente con la microdeleción 3q29 presenta dificultades de aprendizaje, microcefalia límite, dismorfismo facial leve, déficit atencional e impulsividad, y rasgos ansiosos y obsesivos. El paciente con la microduplicación 3q29 recíproca presenta dificultades de aprendizaje, dismorfismo facial leve y un perfil conductual disruptivo no asociado previamente con esta duplicación. Conclusión. Se comparan los fenotipos de estos pacientes y se revisa la bibliografía de pacientes pediátricos con microdeleciones y microduplicaciones 3q29 (AU)

Introduction. The 3q29 microdeletion and microduplication syndromes are characterised by a marked phenotypic heterogeneity, and delayed development and a mild-moderate degree of intellectual disability are the most frequent clinical manifestations. Case reports. Two patients with reciprocal chromosomal aberrations in the 3q29 region. The patient with 3q29 microdeletion presented learning disabilities, borderline microcephaly, mild facial dysmorphism, attentional deficit and impulsiveness, and anxious and obsessive traits. The patient with reciprocal 3q29 microduplication presented learning disabilities, mild facial dysmorphism and a disruptive behavioural profile that was not previously associated with this duplication. Conclusions. The phenotypes of these patients are compared and the literature about paediatric patients with 3q29 microdeletions and microduplications is reviewed (AU)

Deleción en el gen RPS6KA3 en una mujer con un fenotipo clásico del síndrome de Coffin-Lowry incluyendo episodios de caída inducidos por estímulo / Deletion of the RPS6KA3 gene in a female with a classical phenotype of Coffin-Lowry syndrome including stimulus-induced drop attacks

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Enfermedad de Alpers juvenil / Juvenile Alpers disease

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Microdeleción 2q23.1 y hallazgos sindrómicos / Microdeletion 2q23.1 and syndromic findings

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Microdeleción 16p11.2 asociada a convulsiones benignas de la primera infancia / 16p11.2 microdeletion associated to early onset benign childhood seizures

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The influence of valproic acid and carbamazepine treatment on serum biotin and zinc levels and on biotinidase activity.

We determined the serum concentration of biotin, zinc, antiepileptic drugs, and biotinidase enzyme activity in 20 children treated with valproic acid, in 10 children treated with carbamazepine, and in 75 age- and sex-matched healthy controls. There were no significant differences in the serum levels of biotin, and biotinidase enzyme activity between the patients treated with valproic acid, the patients treated with carbamazepine, and the control group. Zinc serum levels were lower in the patients treated with valproic acid and with carbamazepine than in the control group, but within the normal range. Hair loss was observed in 3 patients treated with valproic acid, with normal serum levels of biotin, zinc, and biotinidase activity, and the alopecia disappeared with the oral administration of biotin (10 mg/d) in 3 months. These results suggest that the treatment with valproic acid does not alter the serum levels of biotin, zinc, and biotinidase enzyme activity.

Primary adenosine monophosphate (AMP) deaminase deficiency in a hypotonic infant.

The spectrum of the adenosine monophosphate (AMP) deaminase deficiency ranges from asymptomatic carriers to patients who manifest exercise-induced muscle pain, occasionally rhabdomyolysis, and idiopathic hyperCKemia. However, previous to the introduction of molecular techniques, rare cases with congenital weakness and hypotonia have also been reported. We report a 6-month-old girl with the association of congenital muscle weakness and hypotonia, muscle deficiency of adenosine monophosphate deaminase, and the homozygous C to T mutation at nucleotide 34 of the adenosine monophosphate deaminase-1 gene. This observation indicates the possible existence of a primary adenosine monophosphate deaminase deficiency manifested by congenital muscle weakness and hypotonia.

Comparison of the GlideScope Videolaryngoscope to the standard Macintosh for intubation by pediatric residents in simulated child airway scenarios.

OBJECTIVES: Videolaryngoscopy may facilitate tracheal intubation in difficult airway scenarios. Our objective was to compare the ability of residents to intubate a child manikin using the standard Macintosh laryngoscope and the novel GlideScope. METHODS: Pediatric residents who passed an advanced pediatric life support course were eligible. Four scenarios were proposed: Macintosh (M) and GlideScope (G) "easy" intubation and M and G "difficult"; intubation (cervical immobilization with rigid collar). No participant had previous experience with videolaryngoscope. Each participant performed the 4 scenarios in a random sequence. Time from initiation of intubation procedure to inflation of manikin's chest was recorded, as well as the number of intubation attempts, number of additional maneuvers, dental injury index, and participant's subjective impression. RESULTS: Eighteen subjects were included. Median (range) time for easy airway intubation was 18 seconds (8-120 seconds) with M versus 37 seconds (18-96 seconds) with G (P = 0.029). Time for intubation with cervical immobilization was 19 seconds (9-120 seconds) with M versus 49 seconds (22-120 seconds) with G (P = 0.006). The G intubation in case of cervical immobilization needed significantly more maneuvers than with the M intubation (P = 0.014). There were no significant differences when number of attempts, dental injury index, and participant's subjective difficulty rate were compared. CONCLUSIONS: Without specific training, videolaryngoscope-guided intubation did not improve intubation performance by pediatric residents in this manikin model of normal and simulated difficult intubation caused by a cervical collar in place. To achieve skills with videolaryngoscope intubation in children, a specific training program is needed.

Mutismo electivo y enfermedad mitocondrial: descripción de una nueva asociación / Selective mutism and mitochondrial disease: a description of a new association

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