Molecular biomarkers for neuromuscular disorders - challenges and future perspectives.

There is an ever-growing need for molecular biomarkers in assessing clinical course and diagnosing neuromuscular disorders, as well as in monitoring drug therapy. With the development of high throughput techniques, there has been an acceleration in the discovery of potential biomarkers. It is quite easy to find potential candidates, but difficult to validate them and translate into a clinical setting. Neuromuscular diseases (NMD) are a major challenge in terms of finding potential molecular biomarkers, mainly because of their heterogeneous aetiology and variability in phenotype, their as yet incompletely understood pathophysiology, and their slow clinical progression. Furthermore, it is challenging to assemble a large cohort of patients, as many NMDs are rare diseases. In this literature review, we provide an update on the latest discoveries in DNA, RNA, miRNA, epigenetic, protein, metabolic and cellular biomarkers for NMD. The advantages and potential difficulties of clinical application and the role of identification of biomarker panels are discussed. We have especially sought to highlight translational biomarkers which can be easily transferred to the clinic, where they may eventually present possible future therapies related to molecular biomarker discoveries.