What Is CMT?

Charcot-Marie-Tooth disease affects motor and sensory nerves controlling muscles and sensation respectively.

What is CMT?

CMT is a hereditary nerve disorder causing muscle weakness and sensory loss.

Quick FAQs

What is CMT?

Who gets CMT?

CMT affects people worldwide, across all races and ethnic groups, with a global prevalence of about 1 in 2,500 people (around 125,000 in the US alone, and similar rates in India). In India and Asia, the condition may be underdiagnosed, but studies from countries like India, China, Japan, and Korea indicate a mean onset age of around 16 years, with axonal types more common (about 50% of cases). Higher rates of recessive forms occur in communities with consanguineous marriages, common in parts of South and West Asia.

Anyone can inherit CMT if there's a family history, but many cases are sporadic (no known family link). It affects males and females, though X-linked types (CMTX) may be more severe in males. In India, research from institutions like NIMHANS (Bengaluru) and AIIMS (Delhi) highlights genetic heterogeneity, with CMT1A being common.

What are common symptoms?

Symptoms of CMT usually start gradually in adolescence or early adulthood, but can begin in childhood or later. They often begin in the feet and legs before spreading to the hands and arms. Common signs include:

• Muscle weakness and atrophy: Especially in the lower legs and feet, leading to foot drop (difficulty lifting the front of the foot) and frequent tripping or falls.

• Sensory loss: Numbness, tingling, or reduced sensation to touch, pain, or temperature in a "stocking-glove" pattern (feet/hands first).

• Foot deformities: High arches (pes cavus), hammertoes, flat feet, or inverted feet, which can cause pain, instability, and difficulty wearing shoes.

• Balance and gait issues: Unsteady walking, cramps after exercise, or tremors.

• Other features: Reduced reflexes, fatigue, hand weakness (trouble with buttons or writing), and in some subtypes, additional issues like hearing loss, vision problems, scoliosis, or breathing difficulties.

Severity varies by subtype—mild cases may go unnoticed, while severe ones can lead to wheelchair use. In India, studies note motor-predominant neuropathy and skeletal abnormalities like pes cavus in most patients.

Is there a cure?

Currently, there is no cure for CMT, as it is genetic. However, treatments focus on managing symptoms and improving quality of life. Ongoing research, including gene therapies and clinical trials, offers hope—some trials targeting specific subtypes are in pipeline.

Goto Research Section for more information.

How is CMT diagnosed?

Diagnosis starts with a thorough clinical evaluation and often includes:

• Medical history and physical exam: Assessing symptoms, family history, and signs like foot deformities or reduced reflexes.

• Nerve conduction studies (NCS) and electromyography (EMG): These tests measure nerve signal speed and muscle electrical activity to distinguish demyelinating (slow signals) from axonal (weak signals) types.

• Genetic testing: The gold standard, identifying mutations in genes like PMP22 (for CMT1A). In India, affordable NGS panels are available at labs like NIMHANS or private centers.

• Other tests: MRI for nerve imaging, or biopsy in rare cases.

Early diagnosis is key—consult a neurologist or geneticist. In India, access may vary by region, but urban centers offer advanced testing.

Any Treatment / Management Options?

While no cure exists, options include:

• Physical and occupational therapy: To strengthen muscles and improve mobility.

• Orthotics and aids: Ankle-foot orthoses (AFOs), custom shoes, or canes.

• Pain management: Medications, yoga, or Ayurveda for neuropathic pain.

• Surgery: For deformities like hammertoes or scoliosis.

• Lifestyle: Exercise, nutrition, and avoiding neurotoxic substances.

This page helped me understand CMT clearly and with compassion.

J. Lee

★★★★★