Dominant Intermediate CMT-E is caused by autosomal dominant mutations in the INF2 gene. Symptom onset usually occurs in early childhood and includes the classic CMT symptoms of lower limb weakness and atrophy resulting in gait abnormalities, upper limb weakness and hand muscle atrophy and weakness with dexterity impairment.

CMTers who have CMTDIE almost always experience kidney involvement via a condition called Focal Segmental Glomerulosclerosis Type 5, or FSGS-5 (OMIM 613237). FSGS-5 is a progressive disease of the kidneys that usually results in end-stage renal failure by one’s early 20’s. FSFG-5 is a separate condition from CMTDIE and does occur on its own, but it almost always occurs with CMTDIE.