Charcot-Marie-Tooth disease is caused by duplication of the peripheral myelin protein-22 (PMP22) gene on which chromosome?

Question

Question

This question was previously asked in

SSC CGL 2024 Tier-II Official Paper-I (Held On: 18 Jan, 2025)

Answer 1

The correct answer is chromosome 17.

Key Points

Charcot-Marie-Tooth disease (CMT) is one of the most common inherited neurological disorders, affecting the peripheral nerves.
It is specifically caused by the duplication of the PMP22 gene located on chromosome 17.
The disease leads to the progressive loss of muscle tissue and touch sensation, primarily in the feet, legs, hands, and arms.
CMT can be classified into several types, with CMT1A being the most common form linked to the duplication of PMP22.
Diagnosis often involves genetic testing to identify the duplication of the PMP22 gene on chromosome 17.

Additional Information

PMP22 Gene:
- The Peripheral Myelin Protein 22 (PMP22) gene plays a crucial role in the structure and function of myelin, the protective sheath around nerves.
- Overexpression of PMP22 due to gene duplication disrupts the production of normal myelin, leading to nerve degeneration.
Symptoms of CMT:
- Common symptoms include muscle weakness, decreased muscle size, decreased sensation in extremities, foot deformities, and difficulty walking.
- Symptoms typically appear in adolescence or early adulthood.
Types of CMT:
- CMT1: Caused by abnormalities in myelin.
- CMT2: Caused by abnormalities in the axon of the peripheral nerve cell.
- CMTX: X-linked inheritance pattern, often affecting males more severely.
Treatment and Management:
- There is currently no cure for CMT; treatment focuses on managing symptoms.Physical therapy, occupational therapy, and orthopedic devices can help maintain mobility and function.
- Regular monitoring and supportive care are essential for improving the quality of life for individuals with CMT.