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Coexistence of Charcot‐Marie‐Tooth disease type 1A and anti‐MAG neuropathy
Author(s) -
Piscosquito Giuseppe,
Salsano Ettore,
Ciano Claudia,
Palamara Luisa,
Morbin Michela,
Pareyson Davide
Publication year - 2013
Publication title -
journal of the peripheral nervous system
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1
H-Index - 67
eISSN - 1529-8027
pISSN - 1085-9489
DOI - 10.1111/jns5.12029
Subject(s) - pes cavus , medicine , hereditary motor and sensory neuropathy , sensory loss , tooth disease , intention tremor , nerve biopsy , muscle cramp , weakness , atrophy , postural tremor , peripheral neuropathy , ataxia , surgery , disease , pathology , physical medicine and rehabilitation , anatomy , complication , endocrinology , essential tremor , psychiatry , diabetes mellitus
At age 35, a man with a genetic diagnosis of Charcot‐Marie‐Tooth disease type 1A ( CMT1A ) but no family history of neuropathy and no clinical symptoms developed rapidly progressive loss of balance, distal limb numbness, loss of manual dexterity, and hand tremor. Five years later, he walked with support and had mild pes cavus, marked sensory ataxia, severe leg and hand weakness, absent deep tendon reflexes (DTRs), severe sensory loss, and hand tremor. He had dramatically reduced motor nerve conduction velocity (MNCV), strikingly prolonged motor distal latencies, absent sensory action potentials and lower limb compound muscle action potentials. CMT1A duplication was reconfirmed but the dramatic change in his clinical course suggested a superimposed acquired neuropathy. An IgM ‐kappa monoclonal gammopathy of uncertain significance (MGUS) with high titer anti‐myelin associated glycoprotein (anti‐MAG) activity was found. Nerve biopsy showed severe loss of myelinated fibers with onion bulbs, no evidence of uncompacted myelin, and few IgM deposits. Rituximab was given and he improved. It is very likely that this is a chance association of two rare and slowly progressive neuropathies; rapidly worsening course may have been due to a “double hit”. Interestingly, there are reports of possible superimposition of dysimmune neuropathies on hereditary ones, and the influence of the immune system on inherited neuropathies is matter for debate.