obsolete Charcot-Marie-Tooth disease axonal type 2G

Charcot-Marie-Tooth Disease Axonal Type 2G (CMT2G)

Charcot-Marie-Tooth disease axonal type 2G, also known as CMT2G, is an obsolete term that was previously used to describe a specific form of inherited neuropathy. It is characterized by the degeneration of peripheral sensory and motor neurons, leading to muscle weakness, wasting, and sensory loss.

Key Features:

• Inherited Neuropathy: CMT2G is an autosomal dominant disorder, meaning it can be inherited from one's parents in a dominant pattern.
• Axonal Degeneration: The disease primarily affects the axons of peripheral neurons, leading to degeneration and dysfunction.
• Muscle Weakness and Wasting: Patients with CMT2G experience progressive muscle weakness and wasting, particularly in the distal limbs (hands and feet).
• Sensory Loss: Sensory loss is also a common feature, affecting both motor and sensory functions.

Relevance to Charcot-Marie-Tooth Disease

CMT2G was previously classified as a distinct form of axonal Charcot-Marie-Tooth disease. However, it has since been reclassified due to the discovery of new genetic causes and the expansion of the CMT disease spectrum.

References:

• [1] Vucic et al (2003) reported two families with dominantly inherited axonal neuropathies, which were later classified as CMT2G.
• [14] A study aimed to identify the unknown genetic cause in a large pedigree previously classified with CMT2G.

Note: The term "CMT2G" is now obsolete and has been discontinued.

Common Signs and Symptoms

The signs and symptoms of Charcot-Marie-Tooth disease, axonal type 2G (CMT2G) are similar to those of other forms of CMT. Some common signs and symptoms include:

• Muscle weakness: Muscle weakness is a hallmark symptom of CMT2G, particularly in the distal limbs (hands and feet).
• Muscle atrophy: As muscle weakness progresses, muscle atrophy (shrinkage) can occur.
• Sensory loss: Sensory loss or numbness may be experienced in the hands and feet.
• Distal limb deformities: Deformities such as hammertoes, pes cavus (high arches), and foot dorsiflexor weakness are common.

Progression of Symptoms

Symptoms of CMT2G typically begin to appear in adulthood. The progression of symptoms can vary from person to person but often involves:

• Initial difficulty walking: Patients may experience difficulty walking or frequent tripping due to foot and distal leg weakness.
• Frequent ankle sprains: Frequent ankle sprains are a common complaint as muscle weakness progresses.

Other Symptoms

In addition to the above symptoms, CMT2G can also be associated with:

• Distal amyotrophy: Muscle wasting in the distal limbs (hands and feet).
• Distal muscle weakness: Weakness in the muscles of the hands and feet.

These symptoms are based on information from various sources [1-9].

Diagnostic Tests for CMT Type 2G

Charcot-Marie-Tooth (CMT) disease is a group of disorders characterized by a chronic motor and sensory polyneuropathy. CMT Type 2G is an axonal form of the disease that is dominantly inherited.

• Clinical Presentation: The diagnosis of CMT Type 2G can generally be made based on clinical presentation, nerve conduction studies, and family history [6].
• Electrodiagnostic Tests: Electrodiagnostic tests like electromyography (EMG) and nerve conduction velocity tests are used to confirm the clinical diagnosis [2][3].
• Genetic Testing: Genetic testing can simplify the diagnosis of CMT Type 2G by avoiding invasive procedures, such as nerve biopsy [7]. Early diagnosis can also be achieved through genetic testing [7].
• Nerve Biopsy: Nerve biopsy may be performed in some cases to confirm the diagnosis, but it is not always necessary [2][3].

It's worth noting that genetic testing has been suggested as a way to diagnose specific inherited peripheral neuropathies, including CMT Type 2G [4]. However, the use of genetic testing for diagnostic purposes should be considered on a case-by-case basis.

References:

[1] Not applicable (no relevant information found in context)

[2] Context #3

[3] Context #3

[4] Context #4

[5] Not applicable (no relevant information found in context)

[6] Context #6

[7] Context #7

Current Medical Treatment Options

Unfortunately, there is no proven medical treatment to reverse or slow the natural disease process for the underlying disorder that causes Charcot-Marie-Tooth disease (CMT) axonal type 2G [4]. However, various treatments may help manage symptoms and improve quality of life.

• Pain Management: Neuropathic pain associated with CMT may respond to tricyclic antidepressants or antiepileptic drugs, such as carbamazepine or gabapentin [1].
• Rehabilitation Protocol: A rehabilitation protocol that includes muscle recruitment, stretching, and other exercises has been proposed for patients with CMT [6]. This protocol aims to improve muscle strength and function.
• Physical Therapy: Primary management of CMT often includes physiotherapy and occupational therapy to help maintain mobility and independence [10].
• Medications: In some cases, non-steroidal anti-inflammatory drugs (NSAIDs) or other medications may be prescribed to manage symptoms such as pain or inflammation.

Experimental Treatments

While there is no proven medical treatment for CMT axonal type 2G, researchers are exploring new treatments. For example:

• PXT3003: A study on mice found that daily oral PXT3003 treatment restored nerve physiology and improved axonal and myelin integrity [8].
• Ascorbic Acid: Ascorbic acid (vitamin C) has been studied as a potential treatment for CMT, but its effectiveness is still unclear.

Important Note

It's essential to consult with a healthcare professional for medical advice and treatment. They can help determine the best course of action based on individual needs and circumstances.

Based on the search results, it appears that there are different forms of Charcot-Marie-Tooth disease (CMT) with varying degrees of severity and genetic heterogeneity.

Differential diagnosis for CMT2G:

• CMT1X: This form is caused by mutations in the GJB1 gene and can be differentiated from CMT2G based on its distinct genetic cause. [8]
• CMT1B: This form, associated with MPZ gene mutations, also presents a different genetic profile compared to CMT2G. [8]

Other forms of axonal CMT:

• Distal hereditary motor neuropathy (dHMN): This condition is classified under the broader category of axonal CMT and can be considered in the differential diagnosis for CMT2G, although it has a distinct clinical presentation. [10]
• CMT2Z: This form, associated with pathogenic mutations in specific genes, presents a different genetic profile compared to CMT2G. [9]

Key points:

• The differential diagnosis for CMT2G involves considering other forms of axonal CMT and their distinct genetic causes.
• Specific genetic tests can help differentiate between these conditions.
• A thorough clinical evaluation is essential to determine the correct diagnosis.

References:

[8] - Context result 8 [9] - Context result 9 [10] - Context result 10