Assuntos
Doenças Cerebelares/genética , Doenças Cerebelares/patologia , Mutação da Fase de Leitura , Proteínas Mitocondriais/genética , Atrofia , Axônios , Biópsia , Doenças Cerebelares/diagnóstico , Criança , Consanguinidade , Análise Mutacional de DNA , Humanos , Imageamento por Ressonância Magnética , Masculino , Neurônios Motores , Músculos/patologia , Condução Nervosa , Linhagem , Doenças do Sistema Nervoso Periférico/diagnósticoRESUMO
The juvenile neuronal ceroid lipofuscinosis (JNCL, Batten disease, MIM 204200), is an autosomal recessive lysosomal storage disease, which is characterized by ubiquitous accumulation of the lipopigment material ceroid-lipofuscin. It manifests with loss of vision in childhood due to retinal degeneration, followed by seizures and parkinsonism leading to premature death at around 30 years. Eighty-five percent of JNCL patients carry a disease-causing 1.02 kb deletion in the CLN3 gene on chromosome 16. Here we report on a large consanguineous Lebanese family with five affected siblings. Electron microscopy of lymphocytes revealed the presence of fingerprint profiles suggesting JNCL. However, disease progression, especially of mental and motor function was slower as expected for 'classic' JNCL. We thus confirmed the diagnosis by genetic testing and found a new c.597C>A transversion in exon 8, homozygous in all affected family members and not present in 200 alleles of normal controls. The mutation generates a premature termination codon (p.Y199X) truncating the CLN3 protein by 55%. In heterozygous state mutant mRNA transcripts are expressed at the same levels as the wild-type ones, suggesting the absence of nonsense mediated messenger decay. We discuss a potential residual catalytic function of the truncated protein as a cause for the mild phenotype.
Assuntos
Glicoproteínas de Membrana/genética , Chaperonas Moleculares/genética , Mutação/genética , Lipofuscinoses Ceroides Neuronais/genética , Lipofuscinoses Ceroides Neuronais/patologia , Adolescente , Idade de Início , Sequência de Aminoácidos , Criança , Segregação de Cromossomos , Progressão da Doença , Éxons/genética , Feminino , Fundo de Olho , Humanos , Líbano/epidemiologia , Masculino , Dados de Sequência Molecular , Lipofuscinoses Ceroides Neuronais/epidemiologia , Oftalmologia , Linhagem , Adulto JovemRESUMO
In preclinical studies growth hormone and its primary mediator IGF-1 have shown potential to increase muscle mass and strength. A single patient with spinal muscular atrophy reported benefit after compassionate use of growth hormone. Therefore we evaluated the efficacy and safety of growth hormone treatment for spinal muscular atrophy in a multicenter, randomised, double-blind, placebo-controlled, crossover pilot trial. Patients (n = 19) with type II/III spinal muscular atrophy were randomised to receive either somatropin (0.03 mg/kg/day) or placebo subcutaneously for 3 months, followed by a 2-month wash-out phase before 3 months of treatment with the contrary remedy. Changes in upper limb muscle strength (megascore for elbow flexion and hand-grip in Newton) were assessed by hand-held myometry as the primary measure of outcome. Secondary outcome measures included lower limb muscle strength, motor function using the Hammersmith Functional Motor Scale and other functional tests for motor function and pulmonary function. Somatropin treatment did not significantly affect upper limb muscle strength (point estimate mean: 0.08 N, 95% confidence interval (CI:-3.79;3.95, p = 0.965), lower limb muscle strength (point estimate mean: 2.23 N, CI:-2.19;6.63, p = 0.302) or muscle and pulmonary function. Side effects occurring during somatropin treatment corresponded with well-known side effects of growth hormone substitution in patients with growth hormone deficiency. In this pilot study, growth hormone treatment did not improve muscle strength or function in patients with spinal muscular atrophy type II/III.