Characterization of molecular mechanisms underlying the axonal Charcot-Marie-Tooth neuropathy caused by MORC2 mutations.

Mutations in MORC2 lead to an axonal form of Charcot-Marie-Tooth (CMT) neuropathy type 2Z. To date, 31 families have been described with mutations in MORC2, indicating that this gene is frequently involved in axonal CMT cases. While the genetic data clearly establish the causative role of MORC2 in CMT2Z, the impact of its mutations on neuronal biology and their phenotypic consequences in patients remains to be clarified. We show that the full-length form of MORC2 is highly expressed in both embryonic and adult human neural tissues and that Morc2 expression is dynamically regulated in both the developing and the maturing murine nervous system. To determine the effect of the most common MORC2 mutations, p.S87L and p.R252W, we used several in vitro cell culture paradigms. Both mutations induced transcriptional changes in patient-derived fibroblasts and when expressed in rodent sensory neurons. These changes were more pronounced and accompanied by abnormal axonal morphology, in neurons expressing the MORC2 p.S87L mutation, which is associated with a more severe clinical phenotype. These data provide insight into the neuronal specificity of the mutated MORC2-mediated phenotype and highlight the importance of neuronal cell models to study the pathophysiology of CMT2Z.

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.

Mutations in DPAGT1 cause a limb-girdle congenital myasthenic syndrome with tubular aggregates.

Congenital myasthenic syndromes are a heterogeneous group of inherited disorders that arise from impaired signal transmission at the neuromuscular synapse. They are characterized by fatigable muscle weakness. We performed whole-exome sequencing to determine the underlying defect in a group of individuals with an inherited limb-girdle pattern of myasthenic weakness. We identify DPAGT1 as a gene in which mutations cause a congenital myasthenic syndrome. We describe seven different mutations found in five individuals with DPAGT1 mutations. The affected individuals share a number of common clinical features, including involvement of proximal limb muscles, response to treatment with cholinesterase inhibitors and 3,4-diaminopyridine, and the presence of tubular aggregates in muscle biopsies. Analyses of motor endplates from two of the individuals demonstrate a severe reduction of endplate acetylcholine receptors. DPAGT1 is an essential enzyme catalyzing the first committed step of N-linked protein glycosylation. Our findings underscore the importance of N-linked protein glycosylation for proper functioning of the neuromuscular junction. Using the DPAGT1-specific inhibitor tunicamycin, we show that DPAGT1 is required for efficient glycosylation of acetylcholine-receptor subunits and for efficient export of acetylcholine receptors to the cell surface. We suggest that the primary pathogenic mechanism of DPAGT1 mutations is reduced levels of acetylcholine receptors at the endplate region. These individuals share clinical features similar to those of congenital myasthenic syndrome due to GFPT1 mutations, and their disorder might be part of a larger subgroup comprising the congenital myasthenic syndromes that result from defects in the N-linked glycosylation pathway and that manifest through impaired neuromuscular transmission.

Clinical features of congenital myasthenic syndrome due to mutations in DPAGT1.

BACKGROUND: A newly defined congenital myasthenic syndrome (CMS) caused by DPAGT1 mutations has recently been reported. While many other CMS-associated proteins have discrete roles localised to the neuromuscular junction, DPAGT1 is ubiquitously expressed, modifying many proteins, and as such is an unexpected cause of isolated neuromuscular involvement. METHODS: We present detailed clinical characteristics of five patients with CMS caused by DPAGT1 mutations. RESULTS: Patients have prominent limb girdle weakness and minimal craniobulbar symptoms. Tubular aggregates on muscle biopsy are characteristic but may not be apparent on early biopsies. Typical myasthenic features such as pyridostigmine and 3, 4- diaminopyridine responsiveness, and decrement on repetitive nerve stimulation are present. CONCLUSIONS: These patients mimic myopathic disorders and are likely to be under-diagnosed. The descriptions here should facilitate recognition of this disorder. In particular minimal craniobulbar involvement and tubular aggregates on muscle biopsy help to distinguish DPAGT1 CMS from the majority of other forms of CMS. Patients with DPAGT1 CMS share similar clinical features with patients who have CMS caused by mutations in GFPT1, another recently identified CMS subtype.

Triple therapy with darbepoetin alfa, idebenone, and riboflavin in Friedreich's ataxia: an open-label trial.

Minimal objective evidence exists regarding management of Friedreich's ataxia (FRDA). Antioxidant and recombinant human erythropoietin therapies have been considered potential treatments to slow progression of FRDA in a small number of studies. The primary objective of the current study was to test the efficacy, safety, and tolerability of triple therapy-darbepoetin alfa, idebenone, and riboflavin-in FRDA in a clinical pilot study. Patients included in this study were nine females, 16 to 45 years of age (average 28 ± 8), diagnosed with FRDA with confirmed GAA repeat expansion mutations in the FXN gene and a GAA repeat ≥400 on the shorter allele. Patients had a baseline score between 8 and 28.5 (average 20.7 ± 8.3) on the scale for the assessment and rating of ataxia and 94.3 ± 27.2 g/m(2) in left ventricular mass index (LVMI). Patients had been treated with triple therapy with 150 µg darbepoetin alfa every 2 or 3 weeks, 10-20 mg/kg/day idebenone, and 10-15 mg/kg/day riboflavin for 32 ± 19.4 months (range of 8-56 months). Triple therapy was tolerated. Although not statistically significant, improvement of ataxia was observed during the first six 4-month periods of the study. Furthermore, a small decrease in disease progression during the first 2 years of treatment was observed. Long-term statistically nonsignificant improvement of LVMI and stability of the echocardiographic parameters could be considered. Triple therapy may slow disease progression of FRDA.

Axonal neuropathy, long limbs and bumpy tongue: think of MEN2B.

INTRODUCTION: Multiple endocrine neoplasia type 2 (MEN 2) is an uncommon autosomal dominant cancer syndrome which can be associated with nerve conduction abnormalities. METHODS: A 14-year-old boy with a family history of consanguinity developed progressive gait clumsiness, pes cavus, hypotonia, and mucosal tumors of the lips and tongue since the age of 3 years. At age 11 years, he was diagnosed with an hereditary motor neuropathy (Charcot-Marie-Tooth syndrome). RESULTS: Physical examination revealed a Marfanoid habitus, mucocutaneous verrucous tumors, thyroid nodules, and cervical adenopathy. Genetic testing demonstrated the p.M918T mutation in the RET gene, and blood tests showed elevated levels of calcitonin. CONCLUSIONS: Clinical suspicion in MEN2 is crucial for early diagnosis and subsequent therapy. Mucosal neuroma and a Marfanoid habitus are especially useful. Other neurologic manifestations should not disguise the endocrine disorder, because early diagnosis and treatment of medullary thyroid carcinoma determines the prognosis.

Mutational spectrum of the SPG4 (SPAST) and SPG3A (ATL1) genes in Spanish patients with hereditary spastic paraplegia.

BACKGROUND: Hereditary Spastic Paraplegias (HSP) are characterized by progressive spasticity and weakness of the lower limbs. At least 45 loci have been identified in families with autosomal dominant (AD), autosomal recessive (AR), or X-linked hereditary patterns. Mutations in the SPAST (SPG4) and ATL1 (SPG3A) genes would account for about 50% of the ADHSP cases. METHODS: We defined the SPAST and ATL1 mutational spectrum in a total of 370 unrelated HSP index cases from Spain (83% with a pure phenotype). RESULTS: We found 50 SPAST mutations (including two large deletions) in 54 patients and 7 ATL1 mutations in 11 patients. A total of 33 of the SPAST and 3 of the ATL1 were new mutations. A total of 141 (31%) were familial cases, and we found a higher frequency of mutation carriers among these compared to apparently sporadic cases (38% vs. 5%). Five of the SPAST mutations were predicted to affect the pre-mRNA splicing, and in 4 of them we demonstrated this effect at the cDNA level. In addition to large deletions, splicing, frameshifting, and missense mutations, we also found a nucleotide change in the stop codon that would result in a larger ORF. CONCLUSIONS: In a large cohort of Spanish patients with spastic paraplegia, SPAST and ATL1 mutations were found in 15% of the cases. These mutations were more frequent in familial cases (compared to sporadic), and were associated with heterogeneous clinical manifestations.

Posterior fossa tumors in children with neurofibromatosis type 1 (NF1).

BACKGROUND: Tumours of the posterior fossa associated with neurofibromatosis type 1 (NF1) are very infrequent. Series studying this association are seldom reported. PERSONAL EXPERIENCE: In a series of 600 NF1 patients studied during 39 years (1965-2004) only five (0.83%) had posterior fossa tumours. They were studied clinically, radiologically by computerized tomography (CT) or magnetic resonance (MR) and histologically. Four of them had astrocytomas but only in one case was the tumour primarily cerebellar while the tumour was primarily of the brain stem with invasion of the adjacent regions of one or both cerebellar hemispheres in three patients. The fifth tumour was a medulloblastoma that had a survival of 3 years following treatment. The patient with primary cerebellar astrocytoma is apparently cured 7 years after the removal of the tumour. The patients with the brain stem tumours extending to the cerebellum, showed a chronic slowly progressive cerebellar disease, but remain alive at age of more than 20 years (one was lost to follow-up). DISCUSSION AND CONCLUSION: The aim of this study was to present five children (one male and four females) less than 16 years of age when they were initially seen in our service, who had NF1 associates with posterior fossa tumours. This location is very uncommon in patients with NF1, in contrast with those located in other regions, such as pathway optic tumours and brain stem tumours. Most of these tumours are histologically benign (low grade astrocytomas). Only one patient in this series had a medulloblastoma, an exceptionally rare tumour seldom reported in patients with NF1.

Myotonia congenita: mutation spectrum of CLCN1 in Spanish patients.

Myotonia congenita (MC) is a Mendelian inherited genetic disease caused by the mutations in the CLCN1 gene, encoding the main skeletal muscle ion chloride channel (ClC-1). The clinical diagnosis of MC should be suspected in patients presenting myotonia, warm-up phenomenon, a characteristic electromyographic pattern, and/or family history. Here, we describe the largest cohort of MC Spanish patients including their relatives (up to 102 individuals). Genetic testing was performed by CLCN1 sequencing and multiplex ligation-dependent probe amplification (MLPA). Analysis of selected exons of the SCN4A gene, causing paramyotonia congenita, was also performed. Mutation spectrum and analysis of a likely founder effect of c.180+3A>T was achieved by haplotype analysis and association tests. Twenty-eight different pathogenic variants were found in the CLCN1 gene, of which 21 were known mutations and seven not described. Gross deletions/duplications were not detected. Four probands had a pathogenic variant in SCN4A. Two main haplotypes were detected in c.180+3A>T carriers and no statistically significant differences were detected between case and control groups regarding the type of haplotype and its frequencies. A diagnostic yield of 51% was achieved; of which 88% had pathogenic variants in CLCN1 and 12% in SCN4A. The existence of a c.180+3A>T founder effect remains unsolved.

Outcome of arterial ischemic stroke in children with heart disease.

Arterial ischemic strokes (AIS) are rare in childhood. Congenital and acquired heart diseases are one of the most important risk factors of AIS in children. OBJECTIVE: Study the outcome of children with heart disease that have suffered AIS and the factors that influence on prognosis. PATIENTS AND METHODS: We evaluated all children with heart disease who had suffered AIS between 2000 and 2014 in our hospital. RESULTS: Seventy-four children with heart disease suffered an arterial ischemic stroke. 20% of them died and 10% had new AIS during the study period. Fifty-two patients were evaluated an average of six years after AIS. According to the Paediatric Stroke Outcome Scale (PSOM), most of the patients had some degree of impairment, mainly in sensorimotor and in cognitive-behavioural areas. The modified Rankin scale (mRS) showed an unfavourable outcome in 70% of patients (including patients that have died). Upper limb was more functionally impaired than lower limb. Strokes in neonatal period and early life were associated with poor prognosis. Size of stroke, cortical and subcortical involvement and basal ganglia stroke were associated with an unfavourable outcome. Fever in the acute phase and hemiparesis at presentation were also poor prognostic factors. Epilepsy at time of evaluation was also associated with unfavourable outcome. On the other hand, a normal electroencephalogram was associated with favourable outcome. CONCLUSIONS: AIS in children with heart disease had an unfavourable outcome, with impairment in different areas. Epilepsy happened in one third of the patients.

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.

Complexity of the Hereditary Motor and Sensory Neuropathies: Clinical and Cellular Characterization of the MPZ p.D90E Mutation.

Early-onset hereditary motor and sensory neuropathies are rare diseases representing a broad clinical and genetic spectrum. Without a notable familial history, the clinical diagnosis is complicated because acquired causes of peripheral neuropathy, such as inflammatory neuropathies, neuropathies with toxic causes, and nutritional deficiencies, must be considered. We examined the clinical, electrophysiological, and pathologic manifestations of a boy with an initial diagnosis of chronic inflammatory demyelinating polyneuropathy. The progression of the disease despite treatment led to a suspicion of hereditary motor and sensory neuropathy. Genetic testing revealed the presence of the MPZ p.D90E mutation in heterozygosis. To clarify the pathogenicity of this mutation and achieve a conclusive diagnosis, we investigated the MPZ p.D90E mutation through in silico and cellular approaches. This study broadens the clinical phenotype of hereditary motor and sensory neuropathy due to MPZ mutation and emphasises the difficulty of achieving an accurate genetic diagnosis in a sporadic patient to provide an appropriate pharmacologic treatment.

[Guidelines for monitoring late-onset Pompe disease.Sociedad Española de Medicina Interna (SEMI), Sociedad Española de Neurología (SEN) y Sociedad Española de Neumología y CirugíaTorácica (SEPAR)]. / Guía para el seguimiento de la enfermedad de Pompe de inicio tardío.

Although treatment with alglucosidase alfa has helped improve the prognosis of patients with late-onset Pompe disease, both the development of the disease and the effectiveness of the treatment need to be monitored on a regular basis. This is the reason that has led a committee of Spanish experts to draw up a series of guidelines on how to follow up these patients. The committee proposes a model of follow-up tests for late-onset Pompe disease. First of all, the nutritional status and swallowing function must be evaluated. Second, and due to the variability of the clinical features, the committee recommends the simultaneous use of several scales to measure different functions and parameters. Thus, muscular force is assessed with the Medical Research Council scale; motor functioning, with the six-minute walk test and timed tests; disability, with the Rasch-built Pompe-specific Activity scale; respiratory functioning, with measurement of the forced vital capacity and oxygen saturation; and fatigue, with the fatigue intensity scale. Lastly, the safety and tolerability of enzyme replacement therapy are controlled by registering and treating the potential side effects and measurement of the anti-alglucosidase alfa antibodies. A number of different general recommendations are also included.

TITLE: Guia para el seguimiento de la enfermedad de Pompe de inicio tardio.Aunque el tratamiento con alglucosidasa alfa ha contribuido a mejorar el pronostico de los pacientes con enfermedad de Pompe de inicio tardio, es necesario hacer un seguimiento periodico de la evolucion de la enfermedad y de la eficacia del tratamiento. Por este motivo, un comite de expertos españoles ha elaborado una guia para el seguimiento de estos pacientes. El comite propone un modelo de pruebas de seguimiento para la enfermedad de Pompe de inicio tardio. En primer lugar, ha de valorarse el estado nutricional y la funcion deglutoria. En segundo lugar, y debido a la variabilidad del cuadro clinico, el comite recomienda el uso simultaneo de varias escalas que midan distintas funciones y parametros. De este modo, la fuerza muscular se evalua con la escala del Medical Research Council; la funcion motora, con la prueba de la marcha en seis minutos y pruebas cronometradas; la discapacidad, con la escala de actividad especifica de la enfermedad de Pompe construida segun el analisis de Rasch; la funcion respiratoria, con la medida de la capacidad vital forzada y la saturacion de oxigeno; y la fatiga, con la escala de intensidad de la fatiga. Por ultimo, la seguridad y la tolerabilidad del tratamiento enzimatico sustitutivo se controlan con el registro y tratamiento de los potenciales efectos adversos y la medicion de los anticuerpos antialglucosidasa alfa. Se incluyen tambien diversas recomendaciones generales.

Cobb syndrome: case report.

We present a 7-year-old boy in whom cutaneous hemangioma and intramedullary and paraspinal arteriovenous malformations were associated. Magnetic resonance arteriography revealed the presence of the two arterovenous malformations, and the selective intercostal arteriography demonstrated that the intraspinal and paraspinal arteriovenous malformations were supplied by the same intercostal arteries. Rubbing the back was required to detect the cutaneous changes, which were only suspected by casual inspection.

[Voluminous plexiform neurofibromas of the neck region in neurofibromatosis 1]. / Neurofibromas plexiformes voluminosos de cuello en la neurofibromatosis tipo 1.

AIM. To present the clinic, imaging and evolutive characteristics of a series of patients with neurofibromatosis 1 with voluminous plexiform neurofibromas in the neck (VPNFN) during childhood. PATIENTS AND METHODS. Nine patients (five females and four males) who were diagnosed as VPNFN at ages between 3 and 15 years. The VPNFN widespread to the posterior fossa or the upper thoracic region in some cases. The diagnosis was based on the clinical, imaging and histological findings. RESULTS. One of the tumors was intralaryngeal and caused respiratory difficulties. The other eight patients had the origin of the tumor in several spinal roots of one or both sides and could growth to the posterior fossa and to the upper thoracic region in some cases with displacement of the surrounding organs, especially in three patients, all girls, in whom the tumor reached a voluminous size on one side, that was observed only until 10 to 11 years when the growth ceased. CONCLUSIONS. The VPNFN are histologically benign tumors. Those located in the larynx must be removed because of the respiratory problems, but it is not necessary in cases with other locations despite the voluminous size that can reach in some patients with great displacement of the surrounding organs. The analysis of the results of our series may demonstrate that al least the extralaryngeal tumors only grow to 11-12 years of age. This possibility may make recommendable to retard the surgical treatment as much as possible in cases that it is not necessary.

TITLE: Neurofibromas plexiformes voluminosos de cuello en la neurofibromatosis tipo 1.Objetivo. Presentar las caracteristicas clinicas, de imagen y evolutivas de una serie de pacientes con neurofibromatosis tipo 1 que desarrollaron durante la infancia neurofibromas plexiformes voluminosos en el cuello (NFPVC). Pacientes y metodos. Nueve pacientes (cinco mujeres y cuatro varones) con edades entre 3 y 15 años en el momento del diagnostico de los tumores, que podian extenderse tambien a la fosa posterior y a la zona toracica superior. El diagnostico estuvo basado fundamentalmente en la clinica, la imagen y la histologia. Resultados. Un tumor era intralaringeo y causaba problemas respiratorios. Los otros ocho casos tenian su origen en varias raices espinales de uno o de ambos lados y podian crecer tambien hacia el interior de la fosa posterior y de la region toracica en algunos pacientes, y desplazaban a las estructuras anatomicas vecinas, especialmente en tres casos, todos niñas, en las que el tumor crecio hasta alcanzar gran volumen, especialmente por un lado, parandose el crecimiento entre los 11 y 12 años y no volviendo a crecer mas tarde. Conclusiones. Los NFPVC son tumores histologicamente benignos. La extirpacion es necesaria cuando estan localizados en la laringe por los problemas respiratorios que causan, pero no en los de las otras regiones, pese a que el voluminoso tamaño que alcanzan en algunos casos puede causar exagerados desplazamientos de las estructuras vecinas. El estudio de nuestra serie parece indicar que al menos los tumores extralaringeos solo crecen hasta los 11-12 años. Puede ser recomendable retrasar la cirugia tanto como sea posible si no existe sintomatologia aguda que la haga necesaria.

[Treatment with antisense oligonucleotides in Duchenne's disease]. / Tratamiento con oligonucleotidos antisentido en la enfermedad de Duchenne.

In this paper I review the results of the treatments directed to modify the mRNA of dystrophin with the goal of converting the severe Duchenne type to the milder Becker muscular dystrophy. Antisense oligomers potential to modify Duchenne muscular dystrophy (DMD) gene expression and therapeutic strategies to induce ribosomal read-through of nonsense mutations (PTC124) are described. They are an important advance in the treatment of DMD, so far unspecific. Significant expression of new dystrophin is observed in biopsies of peripheral muscle, although the functional improvement is not so encouraging. New modification of chemistries are expected to improve the liberation, broad distribution in muscles, as well as their efficacy and safety enough to allow a positive chronic treatment of DMD.

Mitochondrial DNA polymorphisms/haplogroups in hereditary spastic paraplegia.

Mitochondrial dysfunction could contribute to the development of spastic paraplegia. Among others, two of the genes implicated in hereditary spastic paraplegia encoded mitochondrial proteins and some of the clinical features frequently found in these patients resemble those observed in patients with mitochondrial DNA (mtDNA) mutations. We investigated the association between common mtDNA polymorphisms and spastic paraplegia. The ten mtDNA polymorphisms that defined the common European haplogroups were determined in 424 patients, 19% with a complicated phenotype. A rare haplogroup was associated with the disease in patients without a SPG3A, SPG4, or SPG7 mutation. Allele 10398G was more frequent among patients with a pure versus complicated phenotype. This mtDNA polymorphism was previously associated with the risk of developing other neurodegenerative diseases. In conclusion, some mtDNA polymorphisms could contribute to the development of spastic paraplegia or act as modifiers of the phenotype.

Screening for mutations in Spanish families with myotonia. Functional analysis of novel mutations in CLCN1 gene.

Myotonia congenita is an inherited muscle disorder caused by mutations in the CLCN1 gene, a voltage-gated chloride channel of skeletal muscle. We have studied 48 families with myotonia, 32 out of them carrying mutations in CLCN1 gene and eight carry mutations in SCN4A gene. We have found 26 different mutations in CLCN1 gene, including 13 not reported previously. Among those 26 mutations, c.180+3A>T in intron 1 is present in nearly one half of the Spanish families in this series, the largest one analyzed in Spain so far. Although scarce data have been published on the frequency of mutation c.180+3A>T in other populations, our data suggest that this mutation is more frequent in Spain than in other European populations. In addition, expression in HEK293 cells of the new missense mutants Tyr137Asp, Gly230Val, Gly233Val, Tyr302His, Gly416Glu, Arg421Cys, Asn567Lys and Gln788Pro, demonstrated that these DNA variants are disease-causing mutations that abrogate chloride currents.

Equimolar nitrous oxide/oxygen versus placebo for procedural pain in children: a randomized trial.

OBJECTIVE: This randomized, single-dose, double-blind, Phase III study was designed to compare the level of procedural pain after use of premixed equimolar mixture of 50% oxygen and nitrous oxide (EMONO) or placebo (premixed 50% nitrogen and oxygen). METHODS: Patients aged 1 to 18 years were randomly assigned to receive EMONO (n = 52) or placebo (n = 48) delivered by inhalation through a facial mask 3 minutes before cutaneous, muscle, or bone/joint procedures. Pain was evaluated (on a scale from 0-10) using a self-reported Faces Pain Scale-Revised (FPS-R) or a Spanish observational pain scale (LLANTO). Rescue analgesia (with propofol or sevoflurane) was administered if pain scores were greater than or equal to 8. Collaboration, acceptance, ease of use and safety were evaluated by the attending nurse. RESULTS: There were significant differences between the 2 groups (EMONO versus placebo) for both scales (mean values): LLANTO: 3.5 vs 6.7, respectively (P = .01) and FPS-R: 3.2 vs 6.6, respectively (P = .0003). Patients not receiving EMONO (P = .0208)-in particular those aged younger than 3 years (P < .0001)-required more rescue analgesia. There were also significant differences between the 2 groups (EMONO versus placebo) for adequate collaboration (80% vs 35%; P < .0001) and acceptance (73% vs 25%; P < .0001). Ease of use was not significantly different between groups (98.1% vs 95.8%; P > .05). Only 2 patients (in the EMONO group) presented with mild adverse events. CONCLUSIONS: EMONO inhalation was well tolerated and had an estimated analgesic potency of 50%, and it is therefore suitable for minor pediatric procedures.

Major and minor arterial malformations in patients with cutaneous vascular abnormalities.

The association of persistent embryonic arteries and the absence of 1 carotid or vertebral arteries with facial or neck hemangioma or vascular malformation have been frequently described. The abnormalities can involve major or minor vessels. Of 22 patients of our series with this neurocutaneous syndrome, 20 had the origin of both anterior cerebral arteries from the same internal carotid artery. Thirteen patients showed absence or hypoplasia of 1 carotid artery and 10 of 1 vertebral artery; 10 showed persistence of the trigeminal artery; 3 had persistent proatlantal artery; 6 showed the absence of the posterior communicating artery; and 4 had hypoplastic posterior cerebral artery. Other less frequent abnormalities were found in 7 patients. Intellectual level of most patients was either borderline or below normal. Abnormalities in the vascularization and perfusion of the frontal lobes may contribute to the borderline or lower mental level of these patients.