Neurofilament light, biomarkers, and Charcot-Marie-Tooth disease

Sandelius et al.(1) identify neurofilament light (NfL) as a potential biomarker for different types of Charcot-Marie-Tooth disease (CMT) in the current issue of Neurology (R). NfL is increased in CSF and serum in neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and multiple sclerosis (MS).(1) The reader may question, therefore, what is so special about it being identified as a biomarker for yet another disorder. The answer is that clinical trials are emerging for several CMT forms and the lack of a nerve-specific biomarker has been a limiting factor in designing and performing these trials.