Molecular characterization of Spanish patients with MECP2 duplication syndrome.

MECP2 duplication syndrome (MDS) is an X-linked neurodevelopmental disorder characterized by a severe to profound intellectual disability, early onset hypotonia and diverse psycho-motor and behavioural features. To date, fewer than 200 cases have been published. We report the clinical and molecular characterization of a Spanish MDS cohort that included 19 boys and 2 girls. Clinical suspicions were confirmed by array comparative genomic hybridization and multiplex ligation-dependent probe amplification (MLPA). Using, a custom in-house MLPA assay, we performed a thorough study of the minimal duplicated region, from which we concluded a complete duplication of both MECP2 and IRAK1 was necessary for a correct MDS diagnosis, as patients with partial MECP2 duplications lacked some typical clinical traits present in other MDS patients. In addition, the duplication location may be related to phenotypic severity. This observation may provide a new approach for genotype-phenotype correlations, and thus more personalized genetic counselling.

Validation of a Set of Instruments to Assess Patient- and Caregiver-Oriented Measurements in Spinal Muscular Atrophy: Results of the SMA-TOOL Study.

INTRODUCTION: Outcome measures traditionally used in spinal muscular atrophy (SMA) clinical trials are inadequate to assess the full range of disease severity. The aim of this study was to assess the psychometric properties of a set of existing questionnaires and new items, gathering information on the impact of SMA from the patient and caregiver perspectives. METHODS: This was a multicenter, prospective, noninterventional study including patients with a confirmed diagnosis of 5q-autosomal-recessive SMA aged 8 years and above, or their parents (if aged between 2 and 8 years). The set of outcome measurements included the SMA Independence Scale (SMAIS) patient and caregiver versions, the Neuro-QoL Fatigue Computer Adaptive Test (CAT), the Neuro-QoL Pain Short Form-Pediatric Pain, the PROMIS adult Pain Interference CAT, and new items developed by Fundación Atrofia Muscular España: perceived fatigability, breathing and voice, sleep and rest, and vulnerability. Reliability, construct validity, discriminant validity, and sensitivity to change (4 months from baseline) were measured. RESULTS: A total of 113 patients were included (59.3% 2-17 years old, 59.3% male, and 50.4% with SMA type II). Patients required moderate assistance [mean patient and caregiver SMAIS (SD) scores were 31.1 (12.8) and 7.6 (11.1), respectively]. Perceived fatigability was the most impacted domain, followed by vulnerability. Cronbach's alpha coefficient for perceived fatigability, breathing and voice, and vulnerability total scores were 0.92, 0.88, and 0.85, respectively. The exploratory factor analysis identified the main factors considered in the design, except in the sleep and rest domain. All questionnaires were able to discriminate between the Clinical Global Impression-Severity scores and SMA types. Sensitivity to change was only found for the SMAIS caregiver version and vulnerability items. CONCLUSIONS: This set of outcome measures showed adequate reliability, construct validity, and discriminant validity and may constitute a valuable option to measure symptom severity in patients with SMA.

Genetic landscape of Segawa disease in Spain. Long-term treatment outcomes.

INTRODUCTION: In 2009, we described a possible founder effect of autosomal dominant Segawa disease in Córdoba (Spain) due to mutation c.265C>T (p. Q89*) in the GCH1 gene. We present a retrospective multicentre study aimed at improving our knowledge of Segawa disease in Spain and providing a detailed phenotypic-genotypic description of patients. METHODS: Clinical-genetic information were obtained from standardized questionnaires that were completed by the neurologists attending children and/or adults from 16 Spanish hospitals. RESULTS: Eighty subjects belonging to 24 pedigrees had heterozygous mutations in GCH1. Seven genetic variants have been described only in our cohort of patients, 5 of which are novel mutations. Five families not previously described with p. Q89* were detected in Andalusia due to a possible founder effect. The median latency to diagnosis was 5 years (IQR 0-16). The most frequent signs and/or symptoms were lower limb dystonia (38/56, 67.8%, p = 0.008) and diurnal fluctuations (38/56, 67.8%, p = 0.008). Diurnal fluctuations were not present in the phenotypes other than dystonia. Fifty-three of 56 symptomatic patients were treated with a levodopa/decarboxylase inhibitor for (mean ± SD) 12.4 ± 8.12 years, with 81% at doses lower than 350 mg/day (≤5 mg/kg/d in children). Eleven of 53 (20%) patients had nonresponsive symptoms that affected daily life activities. Dyskinesias (4 subjects) were the most prominent adverse effects. CONCLUSION: This study identifies 5 novel mutations and supports the hypothesis of a founder effect of p. Q89* in Andalusia. New insights are provided for the phenotypes and long-term treatment responses, which may improve early recognition and therapeutic management.

The International Working Group on Neurotransmitter related Disorders (iNTD): A worldwide research project focused on primary and secondary neurotransmitter disorders.

INTRODUCTION: Neurotransmitters are chemical messengers that enable communication between the neurons in the synaptic cleft. Inborn errors of neurotransmitter biosynthesis, breakdown and transport are a group of very rare neurometabolic diseases resulting in neurological impairment at any age from newborn to adulthood. METHODS AND RESULTS: The International Working Group on Neurotransmitter related Disorders (iNTD) is the first international network focusing on the study of primary and secondary neurotransmitter disorders. It was founded with the aim to foster exchange and improve knowledge in the field of these rare diseases. The newly established iNTD patient registry for neurotransmitter related diseases collects longitudinal data on the natural disease course, approach to diagnosis, therapeutic strategies, and quality of life of affected patients. The registry forms the evidence base for the development of consensus guidelines for patients with neurotransmitter related disorders. CONCLUSION: The iNTD network and registry will improve knowledge and strengthen research capacities in the field of inborn neurotransmitter disorders. The evidence-based guidelines will facilitate standardized diagnostic procedures and treatment approaches.

[Experience in molecular diagnostic in hereditary neuropathies in a pediatric tertiary hospital]. / Experiencia en el diagnóstico molecular de neuropatías hereditarias en un hospital pediátrico de tercer nivel.

INTRODUCTION: Charcot-Marie-Tooth (CMT) is the most common hereditary sensory motor neuropathy. Advances in molecular diagnosis have increased the diagnostic possibilities of these patients. PATIENTS AND METHODS: Retrospective study of 36 pediatric patients diagnosed with CMT in a tertiary center in 2003-2015. RESULTS: We found 16 patients were diagnosed by a duplication in PMP22; two cases were diagnosed of hereditary neuropathy with liability to pressure palsies, one with a point mutation in PMP22; a male with a mild demyelinating phenotype, without family history, was diagnosed with GJB1 mutation; in a patient with a peripheral hypotonia at birth and axonal pattern in EMG by mutation in MFN2; a gypsy patient, with consanguineous family, CMT4D, was identified by a mutation in the gene NDRG1; a patient with multiplex congenital arthrogryposis and vocal cord paralysis, whose mother had a scapular-peroneal syndrome, had a congenital spinal muscular atrophy with mild distal axonal neuropathy by mutation in gene TRPV4; three girls, from a gypsy consanguineous family, with axonal CMT with neuromyotonic discharges were diagnosed by a mutation in the gene HINT1; twelve patients haven't molecular diagnosis currently. CONCLUSIONS: CMT1A predominated in our series (44%), as previous studies. We emphasize the description of a patient with a mutation in TRPV4 recently described as a cause of CMT2C and three cases, of gypsy consanguineous family, with the same mutation in HINT1 gene, recently described as a cause of axonal neuropathy with neuromyotonia, autosomal recessive (AR-CMT2). The proportion of patients without molecular diagnosis is similar to main European series.

TITLE: Experiencia en el diagnostico molecular de neuropatias hereditarias en un hospital pediatrico de tercer nivel.Introduccion. La enfermedad de Charcot-Marie-Tooth (CMT) es la neuropatia hereditaria sensitivomotora mas frecuente. Avances en el diagnostico molecular han incrementado las posibilidades diagnosticas de estos pacientes. Pacientes y metodos. Estudio retrospectivo de 36 casos pediatricos diagnosticados de CMT en un centro terciario en el periodo 2003-2015. Resultados. Se identificaron 16 pacientes con CMT1A por una duplicacion en PMP22; dos casos se diagnosticaron de neuropatia hereditaria con predisposicion a paralisis por presion, uno de ellos con una mutacion puntual en PMP22; un varon con un fenotipo leve desmielinizante se diagnostico de CMTX1 por mutacion en GJB1; un paciente con una hipotonia paralitica en el nacimiento y un patron axonal por mutacion en MFN2; un paciente de origen rumano se diagnostico de CMT4D por una mutacion en el gen NDRG1; una paciente con una atrofia muscular espinal congenita distal con neuropatia axonal leve asociada por mutacion en el gen TRPV4; tres niñas de una familia consanguinea de etnia gitana se diagnosticaron de CMT axonal con descargas neuromiotonicas por una mutacion en el gen HINT1; 12 pacientes no tienen diagnostico molecular actualmente, cuatro de ellos de etnia gitana. Conclusiones. CMT1A predomino en nuestra serie (44%), como corresponde a la bibliografia. Destacamos la descripcion de una paciente con una mutacion en TRPV4 recientemente descrita como causa de CMT2C y tres casos de una misma familia consanguinea gitana con la misma mutacion en el gen HINT1 recientemente publicada como causa de neuropatia axonal con neuromiotonia autosomica recesiva (AR-CMT2). El porcentaje de casos sin diagnostico molecular es similar al de grandes series europeas.

[Response to everolimus in patients with giant cell astrocytoma associated to tuberous sclerosis complex]. / Respuesta a everolimus en pacientes con astrocitoma de celulas gigantes asociado al complejo esclerosis tuberosa.

INTRODUCTION: Subependymal giant cell astrocytomas (SEGA) appear in 5-20% of patients with tuberous sclerosis complex (TSC) and are the most common brain tumours in TSC. They are benign tumours, of a glioneural stock, that develop mainly in the first two decades of life, generally close to the foramen of Monro, and can trigger hydrocephalus and intracranial hypertension. It is one of the leading causes of death in TSC. Recently mTOR inhibitors have proved to be a therapeutic alternative to surgical excision. AIM. To describe our experience of using everolimus to treat patients with SEGA and TSC. PATIENTS AND METHODS: We conducted a prospective study of the responses of patients with TSC and at least one SEGA undergoing growth. RESULTS: Three females and three males with a mean age of 12.3 years received treatment. One patient had previously undergone surgery due to SEGA with hydrocephalus. The maximum mean diameter of the SEGA on beginning treatment was 15.3 mm (range: 11.3-24.8 mm). Treatment was established with everolimus, 2.5 mg/day administered orally in patients with a body surface area < 1.2 m2, and 5 mg/day in patients with a body surface area > 1.2 m2. Two patients presented hypertriglyceridemia; one, anorexia; another, a mouth ulcer; and one, amenorrhoea. The mean reduction in the volume of the SEGA at three months of treatment was 46%, and the reduction remained steady in later control examinations (6-25 months). CONCLUSIONS: Treatment with everolimus reduces the size of SEGA associated with TSC with an adequate safety profile, and constitutes an alternative to surgery in certain cases.

TITLE: Respuesta a everolimus en pacientes con astrocitoma de celulas gigantes asociado al complejo esclerosis tuberosa.Introduccion. Los astrocitomas subependimarios de celulas gigantes (SEGA) se presentan en el 5-20% de los pacientes con complejo esclerosis tuberosa (CET) y son los tumores cerebrales mas comunes en el CET. Son tumores benignos, de estirpe glioneural, que se desarrollan fundamentalmente en las primeras dos decadas de la vida, en general cercanos al foramen de Monro, y pueden ocasionar hidrocefalia e hipertension intracraneal. Constituyen la principal causa de muerte en el CET. Recientemente, los inhibidores mTOR han demostrado ser una alternativa terapeutica a la reseccion quirurgica. Objetivo. Describir nuestra experiencia con everolimus para el tratamiento de pacientes con SEGA y CET. Pacientes y metodos. Estudio prospectivo de la respuesta de los pacientes con CET y al menos un SEGA en crecimiento. Resultados. Recibieron tratamiento tres mujeres y tres varones con una edad media de 12,3 años. Un paciente habia sido previamente intervenido quirurgicamente por SEGA con hidrocefalia. El diametro maximo medio del SEGA al inicio del tratamiento era de 15,3 mm (rango: 11,3-24,8 mm). Se inicio tratamiento con everolimus, 2,5 mg/dia por via oral en pacientes con superficie corporal < 1,2 m2 y 5 mg/dia en pacientes con superficie corporal > 1,2 m2. Dos pacientes presentaron hipertrigliceridemia; uno, anorexia; otro, un afta; y una paciente, amenorrea. La reduccion media del volumen del SEGA a los tres meses de tratamiento fue del 46%, y la reduccion se mantuvo estable en controles posteriores (6-25 meses). Conclusiones. El tratamiento con everolimus disminuye el tamaño de los SEGA asociados a CET con un perfil de seguridad adecuado, y constituye una alternativa a la cirugia en casos seleccionados.