CMT4J is caused by mutations in a gene called FIG4, which is located on chromosome 6. This is a rare form of CMT that wasn’t identified until 2007. Because not many people have this form, our understanding of how it progresses is limited. Symptoms and age of onset are variable; some people have a classic presentation, while others have a slowly progressive neuropathy with more severe changes later in adulthood. CMT4J causes intermediate to slow nerve conductions due to changes in the myelin, the sheath around the nerve “wire.” It is an autosomal recessive form of CMT (CMT4), which means an individual has to have a mutation in each copy of the gene (one from each parent) in order to have symptoms.

 

Not all changes in FIG4 cause disease, however. If one of an individual’s two mutations is benign, he or she would not have CMT4J. CMT4J is frequently misdiagnosed as or co-diagnosed with CIDP (chronic inflammatory demyelinating polyneuropathy). Individuals with CIDP may want to discuss further genetic testing to rule out types of CMT.

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Currently there is an active Natural History Study Please See Below

The purpose of this study is to observe and understand the progression of CMT4J over time. By tracking the natural course of the disease, researchers aim to discover how CMT4J affects individuals and to identify reliable measures of disease progression. CMT4J is a rare and poorly understood condition. By learning more about the disease’s natural history, this study seeks to fill critical knowledge gaps, which could lead to better care and potential treatments. Participation in this study is a chance to contribute to research that may improve the lives of those affected by CMT4J.  

 

Elpida Therapeutics SPC will serve as the sponsor and the study will be conducted at four U.S. sites (University of Texas Southwestern, University of Iowa, the National Institutes of Health, and Stanford University).  

 

Participants will be evaluated every 12 months for up to 5 years. These evaluations will include physical and neurological exams, laboratory tests, measures of CMT outcomes and disability, neuropsychological tests, nerve conduction studies, muscle MRI, pulmonary function tests, and scoliosis series x-rays.  

 

The study seeks to enroll 20 individuals of any age who have a genetically confirmed diagnosis of CMT4J.

 

If you or a family member has been diagnosed with CMT4J and are interested in participating or want further information, please contact Elpida Therapeutics at studyinfo@elpidatx.com. Be sure to mention “CMTA Patients as Partners in Research” when you reach out. For detailed study information, please refer to the clinical trial listing at https://clinicaltrials.gov/ct2/show/NCT06151600.