Assuntos
Canais de Cloreto/genética , Infertilidade Masculina/genética , Leucodistrofia Metacromática/genética , Mutação , Adulto , Canais de Cloro CLC-2 , Predisposição Genética para Doença , Testes Genéticos , Homozigoto , Humanos , Infertilidade Masculina/fisiopatologia , Leucodistrofia Metacromática/diagnóstico , Masculino , Mutação/genéticaRESUMO
BACKGROUND: Compound heterozygosity for a trinucleotide repeat expansion and a point mutation in the FXN gene is a rare cause of Friedreich ataxia (FRDA). METHODS: We identified three Swedish FRDA patients with an FXN p.R165P missense mutation and compared their clinical features with six homozygote trinucleotide repeat expansion carriers. Patients were assessed clinically. Trinucleotide expansion length was determined and lymphocyte frataxin levels measured. RESULTS: p.R165P mutation carriers became wheelchair bound early, but had retained reflexes, better arm function, milder dysarthria, and were more independent in activities of daily living. One p.R165P mutation carrier developed psychosis. Frataxin levels were higher than in homozygous trinucleotide expansion patients. One patient with homozygous trinucleotide repeat expansions and comorbid hemochromatosis had more severe FRDA symptoms than his sibling without hemochromatosis. CONCLUSION: p.R165P patients progress to a less disabling disease state than typical FRDA. Comorbid hemochromatosis may worsen FRDA symptoms through additive effects on iron metabolism.
Assuntos
Ataxia de Friedreich/genética , Hemocromatose/complicações , Proteínas de Ligação ao Ferro/genética , Mutação Puntual , Adolescente , Criança , Pré-Escolar , Ataxia de Friedreich/complicações , Humanos , Expansão das Repetições de Trinucleotídeos , FrataxinaRESUMO
BACKGROUND: Friedreich ataxia is a rare disease caused by GAA-trinucleotide-repeat expansions in the frataxin gene, leading to marked reduction of qualitatively normal frataxin protein. Recently, human recombinant erythropoietin was reported to increase frataxin levels in patients with Friedreich ataxia. METHODS: We performed a 6-month, randomized placebo-controlled, double-blind, dose-response pilot trial to assess the safety and efficacy of erythropoietin in increasing frataxin levels. Sixteen adult patient with Friedreich ataxia were randomly assigned to erythropoietin (n = 11) or matching placebo (n = 5). All patients continued Idebenone treatment (5 mg/kg/day). Treatment consisted of a 6-month scaling-up phase, in which erythropoietin was administered intravenously at the following doses: 20,000 IU every 3 weeks, 40,000 IU every 3 weeks, and 40,000 IU every 2 weeks. RESULTS: Erythropoietin treatment was safe and well tolerated, but did not result in any significant hematological, clinical, or biochemical effects in Friedreich ataxia patients.
Assuntos
Eritropoetina/uso terapêutico , Ataxia de Friedreich/tratamento farmacológico , Ataxia de Friedreich/metabolismo , Proteínas de Ligação ao Ferro/metabolismo , Adulto , Antioxidantes/uso terapêutico , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Masculino , Proteínas Recombinantes/uso terapêutico , Estatísticas não Paramétricas , Fatores de Tempo , Resultado do Tratamento , Ubiquinona/análogos & derivados , Ubiquinona/uso terapêutico , Adulto Jovem , FrataxinaRESUMO
Directed evolution by error-prone PCR was applied to stabilize the cold-active lipase from Pseudomonas fragi (PFL). PFL displays high activity at 10 degrees C, but it is highly unstable even at moderate temperatures. After two rounds of evolution, a variant was generated with a 5-fold increase in half-life at 42 degrees C and a shift of 10 degrees C in the temperature optimum, nevertheless retaining cold-activity. The evolved lipase displayed specific activity higher than the wild type enzyme in the temperature range 29-42 degrees C. Biophysical measurements did not indicate any obvious difference between the improved variant and the wild type enzyme in terms of loss of secondary structure upon heat treatment, nor a shift in the apparent melting temperature.
