A Natural History Study of Charcot-Marie-Tooth 4J (CMT4J)

Charcot-Marie-Tooth (CMT) diseases are the most common inherited motor and sensory neuropathies, composed of a group of pathologically and genetically distinct subtypes ranging from slowly to rapidly progressive disease. CMT4J is a rare subtype of CMT caused by mutations in the FIG4 gene. Pediatric-onset disease can often be characterized by rapid progression of muscle weakness and atrophy, culminating in loss of ambulation and respiratory compromise and premature death. Adult-onset CMT4J can present with a more variable disease course. No prospective natural history study for CMT4J has been reported. This study aims to prospectively investigate the natural history of CMT4J, and concurrently to identify potential outcome measures that could be used in future clinical trials. No investigational product will be provided in the study.