JAMA neurology
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Multicenter Study Comparative Study
Biochemical characterization of patients with in-frame or out-of-frame DMD deletions pertinent to exon 44 or 45 skipping.
In Duchenne muscular dystrophy (DMD), the reading frame of an out-of-frame DMD deletion can be repaired by antisense oligonucleotide (AO)-mediated exon skipping. This creates a shorter dystrophin protein, similar to those expressed in the milder Becker muscular dystrophy (BMD). The skipping of some exons may be more efficacious than others. Patients with exon 44 or 45 skippable deletions (AOs in clinical development) have a less predictable phenotype than those skippable for exon 51, a group in advanced clinical trials. A way to predict the potential of AOs is the study of patients with BMD who have deletions that naturally mimic those that would be achieved by exon skipping. ⋯ Exon 44 or 45 skipping will likely yield lower levels of dystrophin than exon 51 skipping, although the resulting protein is functional enough to often maintain a mild BMD phenotype. Dystrophin transcript stability is an important indicator of dystrophin expression, and transcript instability in DMD compared with BMD should be explored as a potential biomarker of response to AOs. This study is beneficial for the planning, execution, and analysis of clinical trials for exon 44 and 45 skipping.
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In animal studies, brain-derived neurotrophic factor (BDNF) has been shown to impact neuronal survival and function and improve synaptic plasticity and long-term memory. Circulating BDNF levels increase with physical activity and caloric restriction, thus BDNF may mediate some of the observed associations between lifestyle and the risk for dementia. Some prior studies showed lower circulating BDNF in persons with Alzheimer disease (AD) compared with control participants; however, it remains uncertain whether reduced levels precede dementia onset. ⋯ Higher serum BDNF levels may protect against future occurrence of dementia and AD. Our findings suggest a role for BDNF in the biology and possibly in the prevention of dementia and AD, especially in select subgroups of women and older and more highly educated persons.
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The apolipoprotein E (APOE [GenBank, 348; OMIM, 107741]) ε4 allele is a common and well-established genetic risk factor for Alzheimer disease (AD). Sleep consolidation is also associated with AD risk, and previous work suggests that APOE genotype and sleep may interact to influence cognitive function. ⋯ Better sleep consolidation attenuates the effect of APOE genotype on incident AD and development of neurofibrillary tangle pathology. Assessment of sleep consolidation may identify APOE+ individuals at high risk for incident AD, and interventions to enhance sleep consolidation should be studied as potentially useful means to reduce the risk of AD and development of neurofibrillary tangles in APOE ε4+ individuals.
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Reports of pediatric-onset stiff-man syndrome (SMS) are rare. This may be an underrecognized disorder in child neurology practice. ⋯ Childhood-onset SMS is a rare but underrecognized and treatable disorder. Serological and electrophysiological testing aid diagnosis.
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Although median survival in amyotrophic lateral sclerosis (ALS) is 2 to 4 years, survival ranges from months to decades, creating prognostic uncertainty. Strategies to predict prognosis would benefit clinical management and outcomes assessments of clinical trials. ⋯ This study provides proof-of-concept for a novel multivariable modeling strategy to predict ALS prognosis. These results support unbiased biomarker discovery efforts in larger patient cohorts with detailed longitudinal follow-up.