RESUMO
BACKGROUND: Twenty-five patients with Niemann Pick disease type C (age range: 7 months to 44 years) were enrolled in an Italian independent multicenter trial and treated with miglustat for periods from 48 to 96 months. METHODS: Based on the age at onset of neurological manifestations patients' phenotypes were classified as: adult (n = 6), juvenile (n = 9), late infantile (n = 6), early infantile (n = 2). Two patients had an exclusively visceral phenotype. We clinically evaluated patients' neurological involvement, giving a score of severity ranging from 0 (best) to 3 (worst) for gait abnormalities, dystonia, dysmetria, dysarthria, and developmental delay/cognitive impairment, and from 0 to 4 for dysphagia. We calculated a mean composite severity score transforming the original scores proportionally to range from 0 to 1 to summarize the clinical picture of patients and monitor their clinical course. RESULTS: We compared the results after 24 months of treatment in 23 patients showing neurological manifestations. Stabilization or improvement of all parameters was observed in the majority of patients. With the exception of developmental delay/cognitive impairment, these results persisted after 48-96 months in 41 - 55% of the patients (dystonia: 55%, dysarthria: 50%, gait abnormalities: 43%, dysmetria: 41%, respectively). After 24 months of therapy the majority of the evaluable patients (n = 20), demonstrated a stabilization or improvement in the ability to swallow four substances of different consistency (water: 65%, purée: 58%, little pasta: 60%, biscuit: 55%). These results persisted after 48-96 months in 40-50% of patients, with the exception of water swallowing. Stabilization or improvement of the composite severity score was detected in the majority (57%) of 7 patients who were treated early (within 3.5 years from onset) and rarely in patients who received treatment later. CONCLUSIONS: The results of this study suggest that miglustat treatment can improve or stabilize neurological manifestations, at least for a period of time; the severity of clinical conditions at the beginning of treatment can influence the rate of disease progression. This conclusion applies particularly to patients with juvenile or adult onset of the disease. TRIAL REGISTRATION: EudraCT number 2006-005842-35.
Assuntos
1-Desoxinojirimicina/análogos & derivados , Inibidores Enzimáticos/uso terapêutico , Doença de Niemann-Pick Tipo C/tratamento farmacológico , 1-Desoxinojirimicina/administração & dosagem , 1-Desoxinojirimicina/uso terapêutico , Adolescente , Adulto , Criança , Pré-Escolar , Esquema de Medicação , Inibidores Enzimáticos/administração & dosagem , Feminino , Humanos , Lactente , Itália/epidemiologia , Masculino , Doença de Niemann-Pick Tipo C/epidemiologia , Adulto JovemRESUMO
Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a heterogeneous neurodegenerative leukodystrophy caused by recessive mutations in MLC1 or GLIALCAM (types MLC1 and MLC2A) of by dominant mutations in GLIALCAM (MLC2B). GlialCAM functions as an auxiliary subunit of both MLC1 and ClC-2 chloride channel, increasing and modifying the function of the latter. Dominant mutations in GLIALCAM cause transient features of MLC but lacks clinical deterioration. Most recessive and dominant mutations in GLIALCAM studied so far affect the targeting of GlialCAM and its associated subunits. Here, we have investigated two patients with MLC2. The first patient has MLC2B disease, as shown by the improvement in MRI and clinical parameters. In this case, we identified a novel GLIALCAM mutation (p.Q56P) which affected the localization of GlialCAM and its associated subunits, however activating ClC-2 function as the wild-type protein. The second patient has MLC2A disease, as indicated by the lack of clinical improvement, even though, interestingly, the MRI of this patient shows a partial improvement. In this case, we found a recessive mode of inheritance, as the patient harbors two compound heterozygous mutations in GLIALCAM. One of them introduces a stop codon (p.Q56X), whereas the second mutation is a missense mutation (p.R73W), for which we could not identify any trafficking defect or an altered functional effect on ClC-2 in vitro.
Assuntos
Cistos/genética , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/genética , Mutação , Proteínas/genética , Adolescente , Encéfalo/patologia , Canais de Cloro CLC-2 , Proteínas de Ciclo Celular , Criança , Canais de Cloreto/genética , Códon de Terminação , DNA Complementar/metabolismo , Éxons , Feminino , Regulação da Expressão Gênica , Genes Dominantes , Genes Recessivos , Células HEK293 , Células HeLa , Heterozigoto , Humanos , Imageamento por Ressonância Magnética , Técnicas de Patch-Clamp , Fenótipo , Estrutura Secundária de Proteína , Análise de Sequência de DNARESUMO
Brown-Vialetto-van Laere (BVVL) and Fazio-Londe (FL) are rare and clinically overlapping motor neurons syndromes. Recently BVVL has been associated with mutations in C20orf54/hRFT2 and defective riboflavin transport. We compared clinical and laboratory features of 6 patients (age range 11-17 years), with features of BVVL and FL overlap syndromes. Patients were assessed as following: blood levels of riboflavin and redox status, electrophysiological, neuroradiological and pulmonary studies, ALS functional rating scale and molecular genetic analysis. Two patients manifested deafness at ages of 3 and 10 years, and developed later subacute progressive ponto-bulbar palsy. A third patient markedly improved after intravenous immunoglobulins (IVIG), but then relapsed remaining unresponsive to treatment; he was not deaf although had abnormal auditory evoked responses (BAERs). The remaining 3 patients had no deafness, although likewise manifested subacute progressive ponto-bulbar palsy. We found hRFT2 mutations in 3/6 patients manifesting deafness or abnormal BAERs. No patient had reduced riboflavin blood levels. However, on riboflavin supplementation (10mg/kg/day) the most severely affected BVVL patient stopped progression of symptoms following 8 months of treatment. BVVL and FL are severe progressive diseases with overlapping symptoms although only hRFT2 mutated patients manifest deafness. Riboflavin supplementation seems to stabilize and improve progression of the disease.
Assuntos
Paralisia Bulbar Progressiva/genética , Predisposição Genética para Doença/genética , Perda Auditiva Neurossensorial/genética , Adolescente , Paralisia Bulbar Progressiva/complicações , Paralisia Bulbar Progressiva/diagnóstico , Paralisia Bulbar Progressiva/tratamento farmacológico , Criança , Pré-Escolar , Surdez/complicações , Surdez/genética , Progressão da Doença , Potenciais Evocados Auditivos do Tronco Encefálico/efeitos dos fármacos , Potenciais Evocados Auditivos do Tronco Encefálico/genética , Feminino , Perda Auditiva Neurossensorial/complicações , Perda Auditiva Neurossensorial/diagnóstico , Perda Auditiva Neurossensorial/tratamento farmacológico , Humanos , Masculino , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/patologia , Mutação/genética , Riboflavina/sangue , Riboflavina/uso terapêutico , Resultado do TratamentoRESUMO
We investigated two male infant patients who were given a diagnosis of progressive mitochondrial encephalomyopathy on the basis of clinical, biochemical, and morphological features. These patients were born from monozygotic twin sisters and unrelated fathers, suggesting an X-linked trait. Fibroblasts from both showed reduction of respiratory chain (RC) cIII and cIV, but not of cI activities. We found a disease-segregating mutation in the X-linked AIFM1 gene, encoding the Apoptosis-Inducing Factor (AIF) mitochondrion-associated 1 precursor that deletes arginine 201 (R201 del). Under normal conditions, mature AIF is a FAD-dependent NADH oxidase of unknown function and is targeted to the mitochondrial intermembrane space (this form is called AIF(mit)). Upon apoptogenic stimuli, a soluble form (AIF(sol)) is released by proteolytic cleavage and migrates to the nucleus, where it induces "parthanatos," i.e., caspase-independent fragmentation of chromosomal DNA. In vitro, the AIF(R201 del) mutation decreases stability of both AIF(mit) and AIF(sol) and increases the AIF(sol) DNA binding affinity, a prerequisite for nuclear apoptosis. In AIF(R201 del) fibroblasts, staurosporine-induced parthanatos was markedly increased, whereas re-expression of AIF(wt) induced recovery of RC activities. Numerous TUNEL-positive, caspase 3-negative nuclei were visualized in patient #1's muscle, again indicating markedly increased parthanatos in the AIF(R201 del) critical tissues. We conclude that AIF(R201 del) is an unstable mutant variant associated with increased parthanatos-linked cell death. Our data suggest a role for AIF in RC integrity and mtDNA maintenance, at least in some tissues. Interestingly, riboflavin supplementation was associated with prolonged improvement of patient #1's neurological conditions, as well as correction of RC defects in mutant fibroblasts, suggesting that stabilization of the FAD binding in AIF(mit) is beneficial.
Assuntos
Fator de Indução de Apoptose/genética , Apoptose , Genes Ligados ao Cromossomo X , Encefalomiopatias Mitocondriais/genética , Mutação/genética , Fator de Indução de Apoptose/metabolismo , Caspase 3/metabolismo , Simulação por Computador , Primers do DNA/química , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Suplementos Nutricionais , Transporte de Elétrons/fisiologia , Feminino , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Flavina-Adenina Dinucleotídeo/metabolismo , Humanos , Marcação In Situ das Extremidades Cortadas , Recém-Nascido , Imageamento por Ressonância Magnética , Masculino , Encefalomiopatias Mitocondriais/metabolismo , Encefalomiopatias Mitocondriais/patologia , Músculo Esquelético/citologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Doenças do Sistema Nervoso/tratamento farmacológico , Doenças do Sistema Nervoso/etiologia , Linhagem , Poli(ADP-Ribose) Polimerase-1 , Poli(ADP-Ribose) Polimerases/metabolismo , Conformação Proteica , Riboflavina/administração & dosagem , Estaurosporina/farmacologia , Gêmeos MonozigóticosRESUMO
We investigated two unrelated children with an isolated defect of mitochondrial complex III activity. The clinical picture was characterized by a progressive encephalopathy featuring early-onset developmental delay, spasticity, seizures, lactic acidosis, brain atrophy and MRI signal changes in the basal ganglia. Both children were compound heterozygotes for novel mutations in the human bc1 synthesis like (BCS1L) gene, which encodes an AAA mitochondrial protein putatively involved in both iron homeostasis and complex III assembly. The pathogenic role of the mutations was confirmed by complementation assays, using a DeltaBcs1 strain of Saccharomyces cerevisiae. By investigating complex III assembly and the structural features of the BCS1L gene product in skeletal muscle, cultured fibroblasts and lymphoblastoid cell lines from our patients, we have demonstrated, for the first time in a mammalian system, that a major function of BCS1L is to promote the maturation of complex III and, more specifically, the incorporation of the Rieske iron-sulfur protein into the nascent complex. Defective BCS1L leads to the formation of a catalytically inactive, structurally unstable complex III. We have also shown that BCS1L is contained within a high-molecular-weight supramolecular complex which is clearly distinct from complex III intermediates.
Assuntos
Encefalopatias Metabólicas Congênitas/genética , Encefalopatias Metabólicas Congênitas/metabolismo , Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Doenças Mitocondriais/genética , Doenças Mitocondriais/metabolismo , Mutação , ATPases Associadas a Diversas Atividades Celulares , Sequência de Aminoácidos , Sequência de Bases , Encéfalo/patologia , Encefalopatias Metabólicas Congênitas/patologia , Pré-Escolar , DNA Complementar/genética , Complexo III da Cadeia de Transporte de Elétrons/química , Complexo III da Cadeia de Transporte de Elétrons/genética , Feminino , Teste de Complementação Genética , Heterozigoto , Humanos , Proteínas Ferro-Enxofre/química , Proteínas Ferro-Enxofre/metabolismo , Imageamento por Ressonância Magnética , Doenças Mitocondriais/patologia , Dados de Sequência Molecular , Complexos Multiproteicos , Mutagênese Sítio-Dirigida , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Homologia de Sequência de AminoácidosRESUMO
Isolated complex II deficiency is a rare cause of mitochondrial disease in infancy and childhood. No satisfactory treatment is currently available, and affected patients undergo a relentlessly progressive motor and mental deterioration. We report on three complex II-deficient children treated with riboflavin per os, who were followed-up for a mean period of 4.5 years. In two patients with early-onset leukoencephalopathy, neurological condition remained stable or even moderately improved. In the third child, presenting in the first year of life with poor somatic growth and severe hyperlactacidemia, plasma lactate decreased to near-normal levels, and he did not develop signs of neurological involvement. Riboflavin supplementation to the growth medium of cultured fibroblasts resulted in a 2-fold increase of complex II activity in patients, but not in controls.