Description of clinical and genetic features of 122 patients included in the Spanish Pompe registry.

Pompe disease is a rare genetic disorder with an estimated prevalence of 1:60.000. The two main phenotypes are Infantile Onset Pompe Disease (IOPD) and Late Onset Pompe Disease (LOPD). There is no published data from Spain regarding the existing number of cases, regional distribution, clinical features or, access and response to the treatment. We created a registry to collect all these data from patients with Pompe in Spain. Here, we report the data of the 122 patients registered including nine IOPD and 113 LOPD patients. There was a high variability in how the diagnosis was obtained and how the follow-up was performed among different centres. Seven IOPD patients were still alive being all treated with enzymatic replacement therapy (ERT) at last visit. Ninety four of the 113 LOPD patients had muscle weakness of which 81 were receiving ERT. We observed a progressive decline in the results of muscle function tests during follow-up. Overall, the Spanish Pompe Registry is a valuable resource for understanding the demographics, patient's journey and clinical characteristics of patients in Spain. Our data supports the development of agreed guidelines to ensure that the care provided to the patients is standardized across the country.

Hereditary spastic paraplegia associated with a novel homozygous intronic noncanonical splice site variant in the AP4B1 gene.

Pathogenic variants in the AP4B1 gene lead to a rare form of hereditary spastic paraplegia (HSP) known as SPG47. We report on a patient with a clinical suspicion of complicated HSP of the lower limbs with intellectual disability, as well as a novel homozygous noncanonical splice site variant in the AP4B1 gene, in which the effect on splicing was validated by RNA analysis. We sequenced 152 genes associated with HSP using Next-Generation Sequencing (NGS). We isolated total RNA from peripheral blood and generated cDNA using reverse transcription-polymerase chain reaction (RT-PCR). A region of AP4B1 mRNA was amplified by PCR and the fragments obtained were purified from the agarose gel and sequenced. We found a homozygous variant of uncertain significance in the AP4B1 gene NM_006594.4: c.1511-6C>G in the proband. Two different AP4B1 mRNA fragments were obtained in the patient and his carrier parents. The shorter fragment was the predominant fragment in the patient and revealed a deletion with skipping of the AP4B1 exon 10. The patient's longer fragment corresponded to an insertion of the last five nucleotides of AP4B1 intron 9. We confirmed that this variant affects the normal splicing of RNA, sustaining the molecular diagnosis of SPG47 in the patient.

The Role of Respiratory Viruses in Children with Ataxia-Telangiectasia.

BACKGROUND: The impact of respiratory virus infection in patients diagnosed with ataxia-telangiectasia (A-T) has not been well studied. METHODS: A prospective case control study was performed at a National Reference Unit for Primary Immunodeficiency in Spain (from November 2018 to July 2019), including patients younger than 20 years. Symptom questionnaires and nasopharyngeal swabs from multiple respiratory viruses' polymerase chain reaction were collected monthly, and between visits in case of symptoms. RESULTS: Twenty-two individuals were included (11 patients; 11 controls); 164 samples were obtained (81 patients; 84 controls). Patients presented respiratory symptoms more frequently compared with controls (26.5% vs. 3.5%; p < 0.01). Viral detection was observed in 23 (27.3%) episodes in patients and in 15 (17.8%) episodes in controls (p = 0.1). Rhinovirus was the most frequent virus in patients and controls (60% and 53.3%, respectively). Episodes with positive viral detection had associated symptoms in 54% of patients and 18% of controls (p = 0.07). However, patients with A-T presented a similar rate of symptoms during episodes with positive and negative viral detection (26% vs. 27%). The median points given for each questionnaire during symptomatic episodes with negative viral detection were 13/23 points, and during symptomatic positive detection, 7.5/23 points (p = 0.1). In the control group, all but two were asymptomatic during positive viral episodes (score: 2/23 and 3/23 points). Symptomatic episodes, with either positive or negative viral detection, were associated with lower IgA and higher IgM titers and higher CD8+ counts (p < 0.05), particularly when these episodes were moderate/severe. CONCLUSIONS: Patients with A-T more frequently present symptomatic viral infections than controls, especially those with lower IgA and higher IgM titers and higher CD8+ counts.

COVID-19 in children with neuromuscular disorders.

OBJECTIVE: Children with neuromuscular disorders have been assumed to be a particularly vulnerable population since the beginning of COVID-19. Although this is a plausible hypothesis, there is no evidence that complications or mortality rates in neuromuscular patients are higher than in the general population. The aim of this study is to describe the clinical characteristics and outcome of COVID-19 in children with neuromuscular disorders. METHODS: A registry of children with neuromuscular conditions and laboratory-confirmed-SARS-CoV-2 infection was set up by the Neuromuscular Working Group of the Spanish Pediatric Neurology Society (SENEP). Data to be collected were focused on the characteristics and baseline status of the neuromuscular condition and the course of COVID-19. RESULTS: Severe complications were not observed in our series of 29 children with neuromuscular disorders infected by SARS-CoV-2. Eighty-nine percent of patients were clinically categorized as asymptomatic or mild cases and 10% as moderate cases. Patients with a relatively more severe course of COVID-19 had SMA type 1 and were between 1 and 3 years. CONCLUSIONS: The course of COVID-19 in children with neuromuscular disorders may not be as severe as expected. The protective role of young age seems to outweigh the risk factors that are common in neuromuscular patients, such as a decreased respiratory capacity or a weak cough. Further studies are needed to know if this finding can be generalized to children with other chronic diseases.

Posibilidades de tratamiento en la atrofia espinal infantil / Possible treatments for infantile spinal atrophy

Se revisan los nuevos tratamientos de la atrofia muscular espinal (AME) producida por deleción del gen SMN1. Se describen las diferentes posibilidades de incrementar la proteína SMN, de su actividad y persistencia en el organismo. Fármacos neuroprotectores, como olesoxime y riluzol, y fármacos que actúan epigenéticamente, como inhibidores de histona deacetilasa, han mostrado cierto efecto positivo en fases preclínicas pero no han conseguido eficacia en los ensayos clínicos. Podrían proporcionar en un futuro un beneficio añadidos a otros fármacos modificadores genéticos. Los mayores cambios en estudios de modelos del ratón SMA y en fases clínicas se han encontrado con oligonucleótidos antisentido que modifican el splicing del gen SMN2, y se espera que mejoren en el futuro próximo. Recientemente se ha aprobado el nusinersen, un metoxietilo fosforotioato-oligonucleótido antisentido, para uso en pacientes con AME de tipo I una vez demostrada su eficacia en pacientes en el ensayo en fase 3. Se revisan los resultados de este fármaco. Están en marcha modificaciones de oligonucleótidos antisentido que amplíen la liberación en el sistema nervioso y en tejidos periféricos. Hay datos que sugieren eficacia de la terapia génica introduciendo el gen SMN1 mediante virus adenoasociados, actualmente en fase clínica 1. Una constante en estos nuevos tratamientos es que los resultados se optimizan en las etapas precoces de la enfermedad y, mejor aún, en estadio presintomático. Se subraya la importancia de los cuidados generales óptimos, especialmente nutricionales y respiratorios, para conseguir los mejores resultados con las nuevas terapias (AU)

The new treatments of spinal muscular atrophy (SMA) due by SMN1 gene deletions are reviewed. There are several ways to increase the protein SMN, its activity and persistence in the tissues. Neuroprotective drugs as olesoxime or riluzole, and drugs acting by epigenetic mechanisms, as histone deacetylase inhibitors, have shown positive effects in preclinical studies but no clear efficacy in clinical trials. They might give in the future added benefits when used associated to other genetic modifying drugs. The best improvements in murine models of SMA and in clinical trials have been reached with antisense oligonucleotides, drugs that modify the splicing of SMN2, and they are expected to get better in the near future. Nusinersen, a methoxi-ethyl phosphotioate antisense oligonucleotide has recently approved for treatment of patients with SMA type 1 after having proved its efficacy in clinical trial phase 3. The results of nusinersen are reviewed. New modifications of antisense oligonucleotides with better access to brain, spinal cord and peripheral tissues are on the way. There are data of the efficacy of the genetic therapy with SMN1 gene through adenoassociated virus, now in phase 1 trial. A constant feature of these new treatments is that the earlier the treatment, the best are the results, and they are even better in presymptomatic stage. The general standards of care, particularly nutrition and respiratory management are needed in order to reach optimal results with the new therapies (AU)

Cost-minimization analysis in the treatment of spasticity in children with cerebral palsy with botulinum toxin type A: an observational, longitudinal, retrospective study / Análisis de minimización de costes del tratamiento de la espasticidad en niños con parálisis cerebral con toxina botulínica tipo A: un estudio observacional, longitudinal, retrospectivo

Objective: Cost-minimization analysis of onabotulinumtoxinA and abobotulinumtoxinA, taking into account the real dose administered to children with spasticity associated with dynamic equinus foot deformity due to cerebral palsy. Method: A single centre, observational, longitudinal, and retrospective study which included spastic paediatric patients aged 2-to-18-years and treated with onabotulinumtoxinA or abobotulinumtoxinA from December 1995 to October 2012, in the Paediatric Neurology Unit of a first-level Spanish hospital. A longitudinal analysis of spasticity severity was made to confirm the similar efficacy of both treatments. Cost minimization was analyzed using the dose administered and the direct costs (pharmacological and medical visits costs) from the perspective of the National Health System (in euros from 2016). Results: We analyzed 895 patients with paediatric spasticity: 543 were treated only with onabotulinumtoxinA, 292 only with abobotulinumtoxinA, and 60 with both treatments. The mean doses administered were 5.44 U/kg (SD = 2.17) for onabotulinumtoxinA, and 14.73 U/kg (5.26) for abobotulinumtoxinA. The total annual direct cost (pharmacological and medical visits) was €839.56 for onabotulinumtoxinA and €631.23 for abobotulinumtoxinA, which represents a difference of Euro 208.34 per year in favour of treatment with abobotulinumtoxinA. Conclusions: It has been demonstrated that in real clinical practice, the cost per patient and year for treatment of paediatric spasticity was lower when abobotulinumtoxinA was used

Objetivo: Estudio de minimización de costes de onabotulinumtoxinA y de abobotulinumtoxinA, teniendo en cuenta la dosis real administrada, en niños con espasticidad asociada con la deformidad dinámica del pie equino debida a parálisis cerebral. Método: Estudio unicéntrico, observacional, longitudinal y retrospectivo que incluyó pacientes pediátricos espásticos entre 2 y 18 años tratados con onabotulinumtoxinA o abobotulinumtoxinA, entre diciembre del 1995 y octubre del 2012, en el Servicio de Neurología Pediátrica de un hospital español de primer nivel. Se realizó un análisis longitudinal de la gravedad de la espasticidad para confirmar la similar efectividad de ambos tratamientos y proceder al análisis de minimización de costes que contempló las dosis infiltradas y los costes directos (costes farmacológicos y de visitas) desde la perspectiva del Sistema Nacional de Salud (euros 2016). Resultados: Se analizaron 895 pacientes con espasticidad infantil, 543 fueron tratados únicamente con onabotulinumtoxinA, 292 con abobotulinumtoxinA y 60 con ambos tratamientos. Las dosis medias infiltradas obtenidas fueron de 5,44 U/kg (DE = 2,17) para las infiltraciones con onabotulinumtoxinA y de 14,73 U/kg (5,26) para las infiltraciones con abobotulinumto xinA. El coste directo anual total (farmacológico y visitas) fue de 839,56 € para onabotulinumtoxinA y de 631,23 € para abobotulinumtoxinA, lo que supone una diferencia de 208,34 Euros al año a favor del tratamiento con abobotulinumtoxinA. Conclusiones: Se ha mostrado que en práctica clínica real el coste por paciente y año del tratamiento de la espasticidad infantil resulta más económico con la utilización de abobotulinumtoxina

Cost-minimization analysis in the treatment of spasticity in children with cerebral palsy with botulinum toxin type A: an observational, longitudinal, retrospective study.

OBJECTIVE: Cost-minimization analysis of onabotulinumtoxinA and abobotulinumtoxinA, taking into account the real dose administered to children with spasticity associated with dynamic equinus foot deformity due to cerebral palsy. METHOD: A single centre, observational, longitudinal, and retrospective study which included spastic paediatric patients aged 2-to-18-years and treated with onabotulinumtoxinA or abobotulinumtoxinA from December 1995 to October 2012, in the Paediatric Neurology Unit of a first-level Spanish hospital. A longitudinal analysis of spasticity severity was made to confirm the similar efficacy of both treatments. Cost minimization was analyzed using the dose administered and the direct costs (pharmacological and medical visits costs) from the perspective of the National Health System (in euros from 2016). RESULTS: We analyzed 895 patients with paediatric spasticity: 543 were treated only with onabotulinumtoxinA, 292 only with abobotulinumtoxinA, and 60 with both treatments. The mean doses administered were 5.44 U/kg (SD = 2.17) for onabotulinumtoxinA, and 14.73 U/kg (5.26) for abobotulinumto xinA. The total annual direct cost (pharmacological and medical visits) was € 839.56 for onabotulinumtoxinA and € 631.23 for abobotulinumtoxinA, which represents a difference of € 208.34 per year in favour of treatment with abobotulinumtoxinA. CONCLUSIONS: It has been demonstrated that in real clinical practice, the cost per patient and year for treatment of paediatric spasticity was lower when abobotulinumtoxinA was used.

Objetivo: Estudio de minimización de costes de onabotulinumtoxinA y de abobotulinumtoxinA, teniendo en cuenta la dosis real administrada, en ninos con espasticidad asociada con la deformidad dinámica del pie equino debida a parálisis cerebral. Método: Estudio unicéntrico, observacional, longitudinal y retrospectivo que incluyó pacientes pediátricos espásticos entre 2 y 18 anos tratados con onabotulinumtoxinA o abobotulinumtoxinA, entre diciembre del 1995 y octubre del 2012, en el Servicio de Neurología Pediátrica de un hospital espanol de primer nivel. Se realizó un análisis longitudinal de la gravedad de la espasticidad para confirmar la similar efectividad de ambos tratamientos y proceder al análisis de minimización de costes que contempló las dosis infiltradas y los costes directos (costes farmacológicos y de visitas) desde la perspectiva del Sistema Nacional de Salud (euros 2016). Resultados: Se analizaron 895 pacientes con espasticidad infantil, 543 fueron tratados únicamente con onabotulinumtoxinA, 292 con abobotulinumtoxinA y 60 con ambos tratamientos. Las dosis medias infiltradas obtenidas fueron de 5,44 U/kg (DE = 2,17) para las infiltraciones con onabotulinumtoxinA y de 14,73 U/kg (5,26) para las infiltraciones con abobotulinumto xinA. El coste directo anual total (farmacológico y visitas) fue de 839,56 € para onabotulinumtoxinA y de 631,23 € para abobotulinumtoxinA, lo que supone una diferencia de 208,34 € al ano a favor del tratamiento con abobotulinumtoxinA. Conclusiones: Se ha mostrado que en práctica clínica real el coste por paciente y ano del tratamiento de la espasticidad infantil resulta más económico con la utilización de abobotulinumtoxinA.

Disección de arterias vertebrales como causa de evento cerebrovascular agudo en niños / Dissection of vertebral arteries as the cause of acute cerebrovascular events in children

No disponible

Assessment of Targeted Next-Generation Sequencing as a Tool for the Diagnosis of Charcot-Marie-Tooth Disease and Hereditary Motor Neuropathy.

Charcot-Marie-Tooth disease is characterized by broad genetic heterogeneity with >50 known disease-associated genes. Mutations in some of these genes can cause a pure motor form of hereditary motor neuropathy, the genetics of which are poorly characterized. We designed a panel comprising 56 genes associated with Charcot-Marie-Tooth disease/hereditary motor neuropathy. We validated this diagnostic tool by first testing 11 patients with pathological mutations. A cohort of 33 affected subjects was selected for this study. The DNAJB2 c.352+1G>A mutation was detected in two cases; novel changes and/or variants with low frequency (<1%) were found in 12 cases. There were no candidate variants in 18 cases, and amplification failed for one sample. The DNAJB2 c.352+1G>A mutation was also detected in three additional families. On haplotype analysis, all of the patients from these five families shared the same haplotype; therefore, the DNAJB2 c.352+1G>A mutation may be a founder event. Our gene panel allowed us to perform a very rapid and cost-effective screening of genes involved in Charcot-Marie-Tooth disease/hereditary motor neuropathy. Our diagnostic strategy was robust in terms of both coverage and read depth for all of the genes and patient samples. These findings demonstrate the difficulty in achieving a definitive molecular diagnosis because of the complexity of interpreting new variants and the genetic heterogeneity that is associated with these neuropathies.

Mutations in the MORC2 gene cause axonal Charcot-Marie-Tooth disease.

Charcot-Marie-Tooth disease (CMT) is a complex disorder with wide genetic heterogeneity. Here we present a new axonal Charcot-Marie-Tooth disease form, associated with the gene microrchidia family CW-type zinc finger 2 (MORC2). Whole-exome sequencing in a family with autosomal dominant segregation identified the novel MORC2 p.R190W change in four patients. Further mutational screening in our axonal Charcot-Marie-Tooth disease clinical series detected two additional sporadic cases, one patient who also carried the same MORC2 p.R190W mutation and another patient that harboured a MORC2 p.S25L mutation. Genetic and in silico studies strongly supported the pathogenicity of these sequence variants. The phenotype was variable and included patients with congenital or infantile onset, as well as others whose symptoms started in the second decade. The patients with early onset developed a spinal muscular atrophy-like picture, whereas in the later onset cases, the initial symptoms were cramps, distal weakness and sensory impairment. Weakness and atrophy progressed in a random and asymmetric fashion and involved limb girdle muscles, leading to a severe incapacity in adulthood. Sensory loss was always prominent and proportional to disease severity. Electrophysiological studies were consistent with an asymmetric axonal motor and sensory neuropathy, while fasciculations and myokymia were recorded rather frequently by needle electromyography. Sural nerve biopsy revealed pronounced multifocal depletion of myelinated fibres with some regenerative clusters and occasional small onion bulbs. Morc2 is expressed in both axons and Schwann cells of mouse peripheral nerve. Different roles in biological processes have been described for MORC2. As the silencing of Charcot-Marie-Tooth disease genes have been associated with DNA damage response, it is tempting to speculate that a deregulation of this pathway may be linked to the axonal degeneration observed in MORC2 neuropathy, thus adding a new pathogenic mechanism to the long list of causes of Charcot-Marie-Tooth disease.