Volume 9 Issue 8, August 2013

Huntington disease is caused by a CAG repeat expansion in the huntingtin gene. A repeat length of 35 CAGs has long been accepted as the cut-off point beyond which the expansion becomes pathological, but recent findings indicate that intermediate expansions (27–35 repeats) are associated with either a distinct behavioural phenotype or an endophenotype.

A recent study has used whole-exome sequencing, an 'extreme trait' design and imaging genetics to identify coding variants associated with hippocampal volume loss in Alzheimer disease. The research highlights the utility of next-generation sequencing and association studies involving quantitative traits for discovery of disease-related variants in neurodegeneration.

Elderly patients represent a growing proportion of individuals with malignant glioma, but are often excluded from trials owing to their poor prognosis. In a new study, researchers have investigated molecular markers of glioma specifically in elderly patients—are these markers of clinical use?

Data on the incidence of synucleinopathies and tauopathies are limited, and a recently published study has attempted to address this deficit. Confirmation of these proteinopathies currently relies on pathological findings at autopsy, but the new findings raise the possibility of diagnosis during life in some cases.

Mitochondrial diseases are a complex and clinically heterogeneous group of disorders, which— together with our poor understanding of the underlying pathology—makes their diagnosis difficult. Here, DiMauro et al. review current knowledge of defects of the mitochondrial respiratory complex that lead to neurological mitochondrial disorders, outlining diagnostic clues for each disorder, and discussing current therapeutic approaches for these often devastating diseases.

Over the past 15 years, the contribution of genetic factors to development of Parkinson disease has been increasingly recognized. In their Review, Trinh and Farrer summarize the latest findings in this field, highlighting overlapping results from diverse genetics studies. Together, the genes identified suggest a key role for impaired vesicle and mitochondrial dynamics in neurons, which could represent promising targets for novel therapies in Parkinson disease.

In this Review, Reindl et al. discuss a range of CNS disorders that are known to be associated with autoantibodies against myelin oligodendrocyte glycoprotein (MOG). They examine the experimental evidence for a role for MOG autoantibodies in the pathogenesis of demyelinating CNS disorders such as multiple sclerosis and acute disseminated encephalomyelitis, and explore the potential of MOG to function as a biomarker in these diseases.

Chronic low back pain (CLBP) is a highly prevalent and debilitating disorder. Despite progress in understanding the aetiology of CLBP in recent years, this knowledge has not been translated into decreased prevalence or new therapies. In this Review, Morlion discusses interventional pain management, as well as surgical and pharmacotherapy approaches, and reviews the current evidence for the efficacy of these treatments in CLBP.

Despite recent advances in our understanding of the pathophysiology of mitochondrial disease, beneficial treatments for these disorders are lacking. In this Perspectives article, Pfeffer et al. retrospectively review data from clinical trials in mitochondrial disease, and find that many problems arise from publication bias and poor trial design. After discussing these issues, the authors make recommendations for the design of future treatment trials in mitochondrial diseases.