hereditary sensory and autonomic neuropathy type 2

Hereditary Sensory and Autonomic Neuropathy Type 2 (HSAN2) is a rare genetic disorder that primarily affects the sensory nerve cells, which transmit information about sensations such as pain, temperature, touch, and position [1]. This condition usually begins in childhood and affects the nerves that serve the lower legs and feet, as well as the lower arms and hands [2].

The loss of neurons due to HSAN2 leads to a profound and universal sensory loss involving large and small fiber nerves. As a result, individuals with this condition are unable to feel pain, temperature, and touch sensations, which can lead to various complications [3]. The autonomic nervous system is also impaired in people with HSAN2, affecting the regulation of involuntary functions such as heart rate and digestion [4].

HSAN2 is characterized by progressively reduced sensation to pain, temperature, and touch. This condition is inherited and affects all peripheral sensations, although the distribution of somatic involvement may vary [5]. The symptoms of HSAN2 can be severe and debilitating, impacting daily life and requiring proper medical attention.

References: [1] Context 1: Apr 1, 2017 [2] Context 2: Apr 1, 2017 [3] Context 3: Apr 1, 2017 [4] Context 3: Apr 1, 2017 [5] Context 7: by FB Axelrod · 2007

Hereditary Sensory and Autonomic Neuropathy Type 2 (HSAN2) is a rare genetic disorder that affects the nerves, leading to various signs and symptoms.

Common Signs and Symptoms:

• Numbness in Hands and Feet: The first sign of HSAN2 is usually numbness in the hands and feet, which can be followed by tingling sensations [1][3][5][8].
• Loss of Pain and Temperature Sensation: Affected individuals may lose the ability to feel pain or sense hot and cold temperatures [1][3][6].
• Inflamed Fingers or Toes: Symptoms often start with inflamed fingers or toes, especially around the nails [2].

Additional Signs and Symptoms:

• In infants and young children, initial symptoms can include lack of crying with trauma, self-mutilation (tongue, lips), swallowing and feeding problems [4].
• The signs and symptoms of HSAN2 typically begin in infancy or early childhood [5][6][8].

Important Notes:

• Hereditary sensory neuropathy type I (HSN1) is a distinct genetic disorder that belongs to the same group as HSAN2, but it has different characteristics [7].
• The signs and symptoms of HSAN2 can vary in severity and progression from one individual to another.

References: [1] Apr 1, 2017 — The first sign of the condition is usually numbness in the hands and feet. Soon after, affected individuals lose the ability to feel pain or ... [2] Symptoms often start with inflamed fingers or toes, especially around the nails. [3] The first sign of the condition is usually numbness in the hands and feet. Soon after, affected individuals lose the ability to feel pain or sense hot and cold. [4] Initial symptoms (from birth to 3 years) include lack of crying with trauma, self-mutilation (tongue, lips), swallowing and feeding problems. [5] The signs and symptoms of HSAN2 typically begin in infancy or early childhood. The first sign of the condition is usually numbness in the hands and feet. [6] The signs and symptoms of HSAN2 typically begin in infancy or early childhood. The first sign of HSAN2 is usually numbness in the hands and feet. Soon after, ... [7] Hereditary sensory neuropathy type I (HSN1) belongs to a group of similar but distinct genetic disorders characterized by abnormalities affecting the nerves. [8] The signs and symptoms of HSAN2 typically begin in infancy or early childhood. The first sign of the condition is usually numbness in the hands and feet.

Hereditary sensory and autonomic neuropathy type II (HSAN2) can be diagnosed through various tests, which are crucial for confirming the condition.

• Molecular genetic testing is a key diagnostic tool for HSAN2. This test detects variants in specific genes known to cause the condition [1]. It utilizes next-generation sequencing to identify single nucleotide and copy number variants in 23 genes associated with hereditary sensory neuropathies [4].
• Electrophysiologic studies can also support the diagnosis of HSAN. These studies show primarily axonal sensory and often motor peripheral neuropathy, which is characteristic of the condition [9].

Additionally, quantitative sensory testing (QST) may be helpful in autonomic disorders with sensory neuropathy, such as HSAN2. QST permits comparison of sensory thresholds and can aid in diagnosis [8].

It's worth noting that a diagnosis of HSAN is typically based on clinical features, the degree of both sensory and autonomic dysfunction, and biochemical evaluations, with pathologic findings also considered [7].

Available Treatments for Hereditary Sensory and Autonomic Neuropathy Type 2

Hereditary sensory and autonomic neuropathy type 2 (HSAN2) is a rare genetic disorder that affects the sensory nerve cells, leading to severe and progressive symptoms. While there are no specific disease-modifying treatments available for HSAN2, several medications have been approved by the FDA for treatment of polyneuropathy caused by hereditary conditions.

Approved Drugs

Several drugs have been approved for the treatment of polyneuropathy caused by hereditary conditions, which may be beneficial for individuals with HSAN2. These include:

• Patisiran: A medication that targets and reduces the levels of transthyretin (TTR) protein, which is associated with some forms of polyneuropathy.
• Inotersen: Another medication that targets TTR protein and has been shown to improve symptoms in individuals with certain types of polyneuropathy.
• Vutrisiran: A medication that targets TTR protein and has been approved for the treatment of polyneuropathy caused by hereditary transthyretin amyloidosis.

Other Treatments

In addition to these medications, other treatments have been explored for HSAN2. These include:

• Supportive care: This may involve measures such as wearing elastic stockings, taking additional salt in the diet, and using fludrocortisone, a mineralocorticoid.
• Pain management: Individuals with HSAN2 often experience severe pain, which can be managed through various medications and therapies.

Important Note

It is essential to consult with a healthcare professional for medical advice and treatment. They will be able to provide personalized guidance based on individual circumstances and needs.

Citations:

• [3] Several drugs (ie, patisiran, inotersen, vutrisiran) have been approved by the FDA for treatment of polyneuropathy caused by hereditary conditions.
• [7] Other treatments have included wearing of elastic stockings, additional salt in the diet, and use of fludrocortisone, a mineralocorticoid.

Hereditary sensory and autonomic neuropathy type 2 (HSAN2) can be challenging to diagnose, as it shares similar symptoms with other conditions. However, there are several differential diagnoses that should be considered:

• Aromatic L-amino acid decarboxylase deficiency: This is a rare genetic disorder that affects the production of neurotransmitters in the brain and spinal cord. It can cause symptoms similar to HSAN2, such as sensory loss and autonomic dysfunction [6].
• Autonomic dysreflexia syndrome in spinal injuries: This condition occurs when there is damage to the spinal cord, leading to an abnormal response to stimuli. It can cause symptoms like hypertension, bradycardia, and respiratory distress, which may be similar to those seen in HSAN2 [5].

It's essential to consider these differential diagnoses when evaluating patients with suspected HSAN2. A thorough medical history, physical examination, and diagnostic tests such as electromyography (EMG) and nerve conduction studies can help differentiate between these conditions.

References:

[5] Aug 15, 2022 - Differential Diagnoses. [6] Oct 1, 2024 - HSAN type 2, also known as congenital sensory neuropathy (CSN), is autosomal recessively inherited and has 4 subtypes.