Charcot-Marie-Tooth disease- X-linked- 1
Overview
X-Linked Charcot-Marie-Tooth disease is an inherited peripheral neuropathy arising in patients with mutations in the gene encoding connexin 32 (Cx32). Cx32 is expressed at the paranodes and Schmidt-Lantermann incisures of myelinating Schwann cells in which it is believed to form a reflexive pathway between the abaxonal and adaxonal cytoplasmic domains.
Symptoms
* High foot arch * Weak lower leg muscles * Wasted lower leg muscles * Reduced reflexes * Weak foot muscles
Prevention
Prevention of secondary complications: daily heel cord stretching to prevent Achilles' tendon shortening. Surveillance: regular foot examination for pressure sores. Agents/circumstances to avoid: obesity (makes ambulation more difficult); medications (such as vincristine, isoniazid, nitrofurantoin) known to cause nerve damage.
Diagnosis
Molecular genetic testing of the GJB1(Cx32) gene detects about 90% of cases of CMTX1. Such testing is clinically available.
Treatment
Treatment of manifestations: treatment by a team including a neurologist, physiatrist, orthopedic surgeon, and physical and occupational therapist; special shoes and/or ankle/foot orthoses (AFO) to correct foot drop and aid walking; surgery as needed for severe pes cavus; forearm crutches, canes, wheelchairs as needed for mobility; exercise as tolerated.