Charcot-Marie-Tooth disease type 2J with **MPZ** Thr124Met mutation: clinico-electrophysiological and MRI study of a family
Faculty of Pharmaceutical, Biomedical and Veterinary Sciences . Biomedical Sciences
Journal of neurology. - Berlin
University of Antwerp
The purpose of the present study was to describe clinico-electrophysiological features and lower limb muscle MRI findings in a CMT2J pedigree due to MPZ Thr124Met mutation. We examined the proband, aged 56 years, and her affected daughter and son, aged 30 and 29 years. Disease severity in terms of ability to walk and run was established using a nine-point functional disability scale (FDS). We administered the CMT neuropathy score (CMTNS) based on patients symptoms, neurologic examination and neurophysiologic testing. All three patients had non-symptomatic Adies pupil. The proband and her son presented with late-onset lower limb sensorimotor neuropathy and pes cavus; the probands daughter had no signs of polyneuropathy. FDS score was 4 in the proband, 2 in her son, and 0 (normal) in her daughter. In both symptomatic patients, electrophysiological study showed a pattern of length-dependent axonal neuropathy mainly involving lower limb nerves; this was normal in the other patient. CMTNS was 18 in the proband, 12 in her son, and 0 (normal) in her daughter. MRI of foot and leg musculature was normal in the probands daughter, whereas the other two patients showed massive fatty atrophy of intrinsic foot musculature, extensive and diffuse fatty atrophy of leg muscles in the proband, and mild distally accentuated fatty infiltration of calf muscles in her son. Muscle edema, detected only in the probands son, was present in 7 out of 22 (33%) of visualized leg muscles, whereas contrast enhancement occurred in 6 of them. The reported mutation may manifest with either isolated Adies pupil or pupil abnormalities with late-onset sensorimotor lengthdependent axonal polyneuropathy, though the presence of pes cavus might indicate an earlier onset. MRI examination helps to delineate an accurate extent of muscle involvement in the disease.