Hereditary sensory and autonomic neuropathy type 4 (HSAN4) is a rare inherited disorder that affects the peripheral nervous system. It is characterized by the progressive loss of sensation in the hands and feet, as well as autonomic nervous system dysfunction. Symptoms may include numbness, tingling, burning, and pain in the hands and feet, as well as problems with sweating, temperature regulation, and bladder and bowel control. HSAN4 is caused by mutations in the NTRK1 gene and is inherited in an autosomal dominant manner. Treatment is supportive and may include physical therapy, medications, and lifestyle modifications.

Symptoms of Hereditary Sensory and Autonomic Neuropathy Type 4 (HSAN4) can vary from person to person, but may include:

- Loss of sensation in the feet and hands

- Loss of reflexes in the feet and hands
- Muscle weakness
- Loss of coordination
- Abnormal sweating
- Abnormal pupil responses
- Abnormal blood pressure responses
- Abnormal heart rate responses
- Abnormal digestive system responses
- Abnormal bladder and bowel control
- Abnormal temperature regulation
- Abnormal sexual responses
- Abnormal breathing responses
- Abnormal vision responses
- Abnormal hearing responses
- Abnormal balance responses
- Abnormal taste and smell responses
- Abnormal speech responses
- Abnormal swallowing responses

Hereditary sensory and autonomic neuropathy type 4 (HSAN4) is caused by mutations in the NTRK1 gene. This gene provides instructions for making a protein called neurotrophic tyrosine kinase receptor type 1 (TrkA). This protein is involved in the development and maintenance of nerve cells (neurons) in the peripheral nervous system, which is made up of all the nerves that connect the brain and spinal cord to the rest of the body. Mutations in the NTRK1 gene lead to a decrease in the amount of TrkA protein, which disrupts the development and maintenance of peripheral neurons. This can lead to the signs and symptoms of HSAN4.

1. Pain management: Pain medications, such as non-steroidal anti-inflammatory drugs (NSAIDs), opioids, and anticonvulsants, can help to reduce pain associated with HSAN4.

2. Physical therapy: Physical therapy can help to improve strength, balance, and coordination.

3. Occupational therapy: Occupational therapy can help to improve daily functioning and activities of daily living.

4. Assistive devices: Assistive devices, such as braces, canes, and wheelchairs, can help to improve mobility.

5. Surgery: Surgery may be recommended in some cases to correct deformities or to improve function.

6. Gene therapy: Gene therapy is a promising treatment option for HSAN4, but it is still in the early stages of development.

1. Family history of Hereditary sensory and autonomic neuropathy type 4
2. Age: Hereditary sensory and autonomic neuropathy type 4 is more common in adults than in children.
3. Gender: Hereditary sensory and autonomic neuropathy type 4 is more common in males than in females.
4. Ethnicity: Hereditary sensory and autonomic neuropathy type 4 is more common in people of Ashkenazi Jewish descent.
5. Genetic mutations: Hereditary sensory and autonomic neuropathy type 4 is caused by mutations in the SPTLC1 gene.

There is no cure for Hereditary sensory and autonomic neuropathy type 4 (HSAN4). Treatment focuses on managing symptoms and preventing complications. Medications may be prescribed to help manage pain, reduce inflammation, and improve nerve function. Physical therapy, occupational therapy, and other supportive therapies may also be recommended.