Genetic Cause of CMT2 Discovered?

A recent study published in the Journal of Clinical Investigation looked at two unrelated families with CMT2 and identified “autosomal dominant mutations of the canonical Notch ligand Jagged1 (or JAG1)” in them — a likely cause for their CMT that was also backed up by experiments in mice.

Update, October 2026: JAG1-related CMT now has its own OMIM entry, Charcot-Marie-Tooth disease, axonal, type 2HH (CMT2HH, #619574). It is an autosomal dominant axonal CMT, and vocal cord paresis is among its listed features.

The CMT News site covers the JAG1 study in greater detail.

There can, of course, be more than one cause (genetic and otherwise) of CMT. CMT1, for example, can be caused by mutations in many genes, including PMP22, MPZ, EGR2, LITAF, and NEFL (GeneReviews). GJB1 causes the X-linked type CMTX1, and MFN2 causes CMT2A. Now SEPT9 also appears to be a newcomer to the list of CMT genes, based on a report of one German family with autosomal dominant CMT.