Heritable disorders of peripheral nerves with similar clinical features but have different pathology and specific genetic abnormalities.
An inherited disorder of nerves that is characterized by loss of muscle tissue and touch sensation, predominantly in the feet and legs but also in the hands and arms in the advanced stages of disease.
CMT -I type disorders classified by peripheral myelination and with specific protein abnormalities in myelin sheaths or Schwann cells.
Type I affects the glia-derived myelin.
CMT-II type disorders have axonal degeneration.
Presently incurable, this disease is one of the most common inherited neurological disorders, with 37 in 100,000 affected.
Electrophysiological and neuropathological studies can distinguish the two different forms of the mutant disease.
Mutant alleles can segregate in an autosomal dominant, recessive , or X-linked manner.
Single nucleotide polymorphisms and copy number variants confer susceptibility to CMT.
Manifests primarily during second to fourth decades with evolving footdrop.
Patients have distal wasting and weakness of the muscles of the feet, peroneal muscles, anterior tibial muscles and calves.
Impaired large fiber sensory function is reflected in elevated vibration thresholds in toes.
Muscle stretch reflexes are lost, beginning with the ankles.
As a result of long standing muscle imbalance pes cavus (high arches) and hammer toe deformities occur.
Foot drop treated with braces and orthoses.
Lifespan and activities of daily living are normal for most patients.