Cerebral Creatine Deficiency Syndromes

Introduction: Creatine deficiency syndromes are a recently described group of diseases characterized by inborn errors of creatine metabolism. Clinical features include a spectrum of neurodevelopment disorders of diverse severity. They are characterized by low levels of cerebral creatine caused by different pathogenic mutations concerning the genes coding for creatine synthesis enzymes [arginine: glicyne amidinotransferase (AGAT, EC 2.1.4.1) and guanidinoacetate methyltansferase (GAMT, EC 2.1.1.2)], AGAT and GAMT, respectively, or its transporter (CT1 deficiency), SLC6A8. Enzymatic deficiencies are transmitted as autosomal recessive traits, whereas the transporter deficit is X-linked. Objectives: To characterize the clinical and laboratorial presentation, diagnosis and treatment of cerebral creatine deficiency patients, followed in Hospital Pediátrico Carmona da Mota. The awareness of these inborn errors of metabolism as neurological disorders, namely of neurodevelopment, among the medical community is a secondary aim of the present work. Methods and Material: Retrospective analysis of the clinical files of patients followed in our Hospital and diagnosed with cerebral creatine deficiency syndrome. Results: Twelve patients belonging to seven different families were diagnosed with creatine deficiency syndromes. Five presented GAMT deficiency and seven CT1 deficiency. Present ages are 2 to 38 years old. The most common clinical presentations were: global development delay in seven patients (two with epilepsy), and speech delay in two patients. Only one patient had communication and social interaction dysfunction. In all, global development delay in the range of intellectual delay was identified. The pathognomonic pattern of cerebral creatine deficiency in the brain image was demonstrated in eight patients. Pathogenic mutations in GAMT or SLC6A8 genes were identified in all cases. Conclusions: The suspicion of cerebral creatine depletion must be considered in all children presenting unexplained global psychomotor development delay. Pre-symptomatic therapy has shown promising results, especially in GAMT deficiency patients. The high rate of asymptomatic carriers of GAMT mutations in our population makes this disorder eligible to neonatal screening in Portugal

Recessive ataxia with ocular apraxia: review of 22 Portuguese patients.

Abstract BACKGROUND: The recessive ataxias are a heterogeneous group of neurodegenerative disorders characterized by cerebellar ataxia associated with a number of different neurologic, ophthalmologic, or general signs. They are often difficult to classify in clinical terms, except for Friedreich ataxia, ataxia-telangiectasia, and a relatively small group of rare conditions for which the molecular basis has already been defined. OBJECTIVES: To study the clinical presentation and to define diagnostic criteria in a group of Portuguese patients with ataxia and ocular apraxia, an autosomal recessive form without the essential clinical and laboratory features of ataxia-telangiectasia. PATIENTS AND METHODS: We reviewed 22 patients in 11 kindreds, identified through a systematic survey of hereditary ataxias being conducted in Portugal. RESULTS: Age at onset ranged from 1 to 15 years, with a mean of 4.7 years. The duration of symptoms at the time of last examination varied from 5 to 58 years. All patients presented with progressive cerebellar ataxia, the characteristic ocular apraxia, and a peripheral neuropathy. Associated neurologic signs included dystonia, scoliosis, and pes cavus. Magnetic resonance imaging was performed in 16 patients, all of whom showed cerebellar atrophy. CONCLUSIONS: Ataxia with ocular apraxia may be more frequent than postulated before, and may be identified clinically using the following criteria: (1) autosomal recessive transmission; (2) early onset (for most patients in early childhood); (3) combination of cerebellar ataxia, ocular apraxia, and early areflexia, with later appearance of the full picture of peripheral neuropathy; (4) absence of mental retardation, telangiectasia, and immunodeficiency; and (5) the possibility of a long survival, although with severe motor handicap

LAMA2 gene mutation update: Toward a more comprehensive picture of the laminin-α2 variome and its related phenotypes

Congenital muscular dystrophy type 1A (MDC1A) is one of the main subtypes of early-onset muscle disease, caused by disease-associated variants in the laminin-α2 (LAMA2) gene. MDC1A usually presents as a severe neonatal hypotonia and failure to thrive. Muscle weakness compromises normal motor development, leading to the inability to sit unsupported or to walk independently. The phenotype associated with LAMA2 defects has been expanded to include milder and atypical cases, being now collectively known as LAMA2-related muscular dystrophies (LAMA2-MD). Through an international multicenter collaborative effort, 61 new LAMA2 disease-associated variants were identified in 86 patients, representing the largest number of patients and new disease-causing variants in a single report. The collaborative variant collection was supported by the LOVD-powered LAMA2 gene variant database (https://www.LOVD.nl/LAMA2), updated as part of this work. As of December 2017, the database contains 486 unique LAMA2 variants (309 disease-associated), obtained from direct submissions and literature reports. Database content was systematically reviewed and further insights concerning LAMA2-MD are presented. We focus on the impact of missense changes, especially the c.2461A > C (p.Thr821Pro) variant and its association with late-onset LAMA2-MD. Finally, we report diagnostically challenging cases, highlighting the relevance of modern genetic analysis in the characterization of clinically heterogeneous muscle diseases.info:eu-repo/semantics/publishedVersio

A child with Miller Fisher Syndrome

Introdução: O síndrome de Miller Fisher, variante do síndrome de Guillain-Barré, é uma doença desmielinizante inflamatória aguda, que é rara em idade pediátrica. O seu diagnóstico é baseado na tríade oftalmoplegia, ataxia e arreflexia. Em cerca de metade dos casos está descrita uma intercorrência infecciosa precedendo os sintomas neurológicos em cinco a dez dias. Caso clínico: Os autores relatam o caso de uma criança de cinco anos de idade com disartria, ataxia e oftalmoplegia após episódio de gastroenterite aguda na semana prévia ao início da sintomatologia. À observação apresentava disartria, parésia bilateral do VI par, fraqueza muscular distal (de predomínio nos membros direitos) com ausência dos reflexos osteotendinosos aquilianos. A investigação analítica e imagiológica inicial não revelou alterações. O resultado do electromiografia foi compatível com poliradiculoneuropatia subaguda. O diagnóstico de síndrome Miller Fisher foi efectuado após exclusão de outras etiologias. A evolução clínica foi favorável, sem insuficiência respiratória ou outras complicações, com melhoria gradual dos défices neurológicos. Houve recuperação da ataxia ao fim de quatro semanas e da oftalmoplegia três meses após o diagnóstico. Conclusões: O síndrome Miller Fisher é extremamente raro em idade pediátrica e constitui um desafi o diagnóstico neste grupo etário. O prognóstico é habitualmente favorável. A propósito deste caso são discutidos os principais diagnósticos diferenciais. ABSTRACT Background: Miller Fisher syndrome, a variant of Guillain-Barré syndrome, is an acute inflammatory demyelinating disease that is rare in children. The diagnosis is based on the triad of ophthalmoplegia, ataxia and areflexia. In about half of the cases there is an infectious complication preceding neurologic symptoms in five to ten days. Case report: We describe the case of a five year-old boy who presented with a three-day history of diplopia, dysarthria and gait disturbance following an acute gastroenteritis. On examination he was found to have ataxia, areflexia and ophthalmoplegia. The laboratorial and imaging investigations were normal. The results of electromyogram were consistent with subacute polyradiculoneuropathy. The diagnosis of Miller Fisher syndrome was made after the exclusion of other conditions. The clinical outcome was favorable without respiratory failure or other complications, with gradual improvement of neurological deficits. Ataxia was restored in four weeks and ophthalmoplegia improved three months later. Conclusions: Miller Fisher syndrome is extremely rare in children and is a diagnostic challenge at those ages. Outcome is usually good. This report outlines the frequency of Miller Fisher syndrome and lists the differential diagnoses that should be considered

Screening for Pompe Disease in a Portuguese High Risk Population

Pompe disease is a rare metabolic disorder with available enzymatic replacement therapy. Contrasting with the classic infantile form, the others subtypes have a heterogeneous presentation that makes an early and accurate diagnosis difficult. We conducted a prospective, multicenter, observational study to identify undiagnosed patients. During a one-year period, patients followed in Portuguese neuromuscular outpatient clinics with proximal muscle weakness affecting upper and/or lower limbs, hyperCKemia in two or more determinations or hypotonia and hyperCKemia, were screened for acid α-glucosidase deficiency by dried blood spots. Lysosomal acid-alpha-1,4-glucosidase activity was determined by tandem mass spectrometry and positive results were confirmed by molecular study. From the 99 patients screened, Pompe disease was confirmed in 4, with age of onset ranging from 2.5 to 48 years, all with limb girdle muscle weakness, corresponding to a frequency of 4% in our cohort and 4.9% of limb girdle muscle weakness. Screening for Pompe disease in high risk populations, using dried blood spots, was already performed in some European populations. Apart from two negative Scandinavian studies, positive cases were confirmed in 2.8-7.9% of patients presenting with limb girdle muscle weakness and in 0-2.5% with isolated hyperCKemia.info:eu-repo/semantics/publishedVersio

Screening for Pompe disease in a Portuguese high risk population

Pompe disease is a rare metabolic disorder with available enzymatic replacement therapy. Contrasting with the classic infantile form, the others subtypes have a heterogeneous presentation that makes an early and accurate diagnosis difficult. We conducted a prospective, multicenter, observational study to identify undiagnosed patients. During a one-year period, patients followed in Portuguese neuromuscular outpatient clinics with proximal muscle weakness affecting upper and/or lower limbs, hyperCKemia in two or more determinations or hypotonia and hyperCKemia, were screened for acid α-glucosidase deficiency by dried blood spots. Lysosomal acid-alpha-1,4-glucosidase activity was determined by tandem mass spectrometry and positive results were confirmed by molecular study. From the 99 patients screened, Pompe disease was confirmed in 4, with age of onset ranging from 2.5 to 48 years, all with limb girdle muscle weakness, corresponding to a frequency of 4% in our cohort and 4.9% of limb girdle muscle weakness. Screening for Pompe disease in high risk populations, using dried blood spots, was already performed in some European populations. Apart from two negative Scandinavian studies, positive cases were confirmed in 2.8-7.9% of patients presenting with limb girdle muscle weakness and in 0-2.5% with isolated hyperCKemia.info:eu-repo/semantics/publishedVersio