hereditary sensory and autonomic neuropathy type 2B

Hereditary sensory and autonomic neuropathy type 2B (HSAN2B) is a rare genetic disorder that primarily affects the sensory nerve cells, which transmit information about sensations such as pain, temperature, and touch to the brain. This condition is characterized by progressive sensory deficit, with variable involvement of the autonomic nervous system and motor function.

Key Features:

• Progressive Sensory Deficit: The inability to feel pain, temperature, and touch sensations due to the gradual destruction of nerve cells.
• Variable Autonomic Involvement: Impairment of the autonomic nervous system, which regulates various bodily functions such as heart rate, digestion, and blood pressure.
• Motor Involvement: Some individuals may experience motor symptoms, although this is not a consistent feature of HSAN2B.

Age of Onset:

• The condition typically begins in early childhood, with some cases reported at birth or before puberty.

Inheritance Pattern:

• HSAN2B is inherited in an autosomal recessive manner, meaning that an individual must inherit two copies of the mutated gene (one from each parent) to express the condition.

Other Inherited Causes:

• It's worth noting that there are other inherited causes of autonomic neuropathy, including Fabry disease, triple A syndrome, Navajo Indian neuropathy, Tangier disease, and multiple endocrine neoplasia type 2B (MEN 2B).

References:

• [1] HSAN2B is characterized by progressive sensory deficit and variable autonomic and motor involvement. Because few RETREG1 mutations have been reported, there is limited information available on this condition.
• [9] The first reported cases of HSAN2B were documented in 2009, with subsequent studies confirming the existence of this rare genetic disorder.
• [10] Hereditary sensory and autonomic neuropathy type IIB (HSAN2B) is an autosomal recessive neurologic disorder characterized by early childhood onset of distal sensory loss.

Please note that HSAN2B is a rare condition, and more research is needed to fully understand its characteristics and implications.

Hereditary sensory and autonomic neuropathy type 2B (HSAN2B) is a rare genetic disorder that affects the nerves, causing a range of symptoms. The signs and symptoms of HSAN2B typically begin in infancy or early childhood.

Common Symptoms:

• Numbness and tingling sensations in the hands and feet [1]
• Inflamed fingers or toes, especially around the nails [2]
• Loss of ability to feel pain or sense hot and cold [3]
• Trophic changes are present in the upper and lower extremities [5]

Early Childhood Symptoms:

• Lack of crying with trauma
• Self-mutilation (tongue, lips)
• Swallowing and feeding problems
• Gastroesophageal reflux disease (GERD) symptoms such as:
  • Difficulty digesting food
  • Feeling full after a few bites of food
  • Loss of appetite
  • Diarrhea
  • Constipation
  • Abdominal bloating
  • Nausea
  • Vomiting [4]

Other Symptoms:

• Pain, temperature, and position senses are involved [5]
• Difficulty with digestion and absorption of nutrients

It's essential to note that the symptoms of HSAN2B can vary in severity and may progress over time. If you or a loved one is experiencing any of these symptoms, it's crucial to consult a healthcare professional for proper diagnosis and treatment.

References: [1] Apr 1, 2017 — The signs and symptoms of HSAN2 typically begin in infancy or early childhood. [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. Gastroesophageal ... [5] by FB Axelrod · 2007 · Cited by 287 — Pain, temperature, and position senses are involved. Trophic changes are present in the upper and lower extremities. At one time, HSAN II was termed 'Morvan's ...

Hereditary Sensory and Autonomic Neuropathy Type 2B (HSAN2B) is a rare genetic disorder that primarily affects the sensory nerve cells (sensory neurons). Diagnosing HSAN2B can be challenging, but several diagnostic tests can help confirm the condition.

Electrophysiologic Studies: These studies are crucial in diagnosing HSAN2B. They show primarily axonal sensory and often motor peripheral neuropathy [8]. This means that electrophysiologic studies can detect abnormalities in the electrical activity of the nerves, which is a hallmark of HSAN2B.

Clinical Features: The diagnosis of HSAN2B is also based on clinical features, including:

• Family History: A family history of similar symptoms or conditions can suggest a genetic etiology [7].
• Sensory and Autonomic Dysfunction: Patients with HSAN2B often experience sensory and autonomic dysfunction, which can manifest as numbness, tingling, or pain in the hands and feet, as well as problems with digestion, sweating, and heart rate regulation.
• Generalized Polyneuropathy: A generalized polyneuropathy, where multiple nerves are affected, is a common feature of HSAN2B [7].

Genetic Testing: Genetic testing can also be used to diagnose HSAN2B. The Invitae Hereditary Sensory and Autonomic Neuropathy Panel analyzes genes associated with hereditary sensory and autonomic neuropathies (HSANs), including the gene responsible for HSAN2B [1]. This panel can detect single nucleotide and copy number variants in 23 genes associated with hereditary sensory and autonomic neuropathy.

Other Diagnostic Tests: Other diagnostic tests, such as nerve conduction studies and electromyography, may also be used to support the diagnosis of HSAN2B. However, these tests are not specific for HSAN2B and should be interpreted in conjunction with clinical features and family history.

In summary, diagnosing HSAN2B requires a combination of clinical evaluation, electrophysiologic studies, and genetic testing. A thorough diagnostic workup can help confirm the condition and guide treatment decisions.

References: [1] The Invitae Hereditary Sensory and Autonomic Neuropathy Panel. [7] Mar 1, 2024 — A genetic etiology of a peripheral neuropathy is generally suggested by generalized polyneuropathy, family history, lack of positive sensory ... [8] The diagnosis of HSAN is supported by electrophysiologic studies that show primarily axonal sensory and often motor peripheral neuropathy. Together, these ...

Hereditary Sensory and Autonomic Neuropathy Type II (HSAN2) is a rare genetic disorder that affects the sensory nerve cells, leading to progressive loss of sensation in large and small fiber nerves. While there is no cure for HSAN2, several drug treatments have been approved or are being researched to manage its symptoms.

Approved Drug Treatments:

• Patisiran: This medication has been approved by the FDA for the treatment of polyneuropathy caused by hereditary transthyretin amyloidosis (hATTR), a related condition. However, it may also be effective in treating HSAN2 [5].
• Inotersen: Another FDA-approved drug, inotersen is used to treat hATTR and may have potential benefits for patients with HSAN2 [5].
• Vutrisiran: This medication has been approved by the FDA for the treatment of polyneuropathy caused by hereditary transthyretin amyloidosis (hATTR) and may also be effective in treating HSAN2 [5].

Other Potential Treatments:

• Gene therapies are not currently available for HSAN, but researchers are exploring their potential benefits. Selecting the correct genetic tests relies on the clinical context, including the specific type of HSAN being diagnosed [8].
• Other treatments that have been tried in patients with HSAN2 include wearing elastic stockings, increasing salt intake, and using fludrocortisone, a mineralocorticoid [9].

It's essential to note that these drug treatments are not specifically approved for HSAN2, but may be effective based on their mechanism of action. Consultation with a healthcare professional is necessary to determine the best course of treatment for individual patients.

References: [5] Aug 15, 2022 — Several drugs (ie, patisiran, inotersen, vutrisiran) have been approved by the FDA for treatment of polyneuropathy caused by hereditary ... [8] Currently, no gene therapies are available for varieties of HSAN, and selecting the correct genetic tests relies on the clinical context, including the ... [9] by FB Axelrod · 2007 · Cited by 287 — Other treatments have included wearing of elastic stockings, additional salt in the diet, and use of fludrocortisone, a mineralocorticoid, and ...

Hereditary sensory and autonomic neuropathy (HSAN) type 2B, also known as congenital sensory neuropathy (CSN), is a rare genetic disorder that affects the nerves serving the lower legs and feet, and the lower arms and hands. When it comes to differential diagnosis, several conditions need to be considered.

Conditions to Rule Out:

• Multiple System Atrophy: This is a progressive neurodegenerative disorder that affects movement, balance, and autonomic functions. It can present with similar symptoms to HSAN type 2B, such as sensory loss and autonomic dysfunction.
• Parkinson-Plus Syndromes: These are a group of neurodegenerative disorders that resemble Parkinson's disease but have distinct features. They can include conditions like Progressive Supranuclear Palsy (PSP), which affects movement and balance.
• Progressive Supranuclear Palsy: This is a rare brain disorder that affects movement, balance, and eye movements. It can present with similar symptoms to HSAN type 2B, such as sensory loss and autonomic dysfunction.

Other Hereditary Sensory and Autonomic Neuropathies (HSANs)

• HSAN II: This is another subtype of hereditary sensory neuropathy that affects the nerves serving the lower limbs. It can present with similar symptoms to HSAN type 2B, such as sensory loss and autonomic dysfunction.
• Diabetic Foot: While not a genetic disorder per se, diabetic foot can present with similar symptoms to HSAN type 2B, such as sensory loss and autonomic dysfunction.

Key Diagnostic Features:

To diagnose HSAN type 2B accurately, it is essential to consider the following key features:

• Childhood-onset sensory loss
• Reduced sweating
• Auto-amputations
• Charcot neuroarthropathy of ankles and feet

These features can help differentiate HSAN type 2B from other conditions that may present with similar symptoms.

References:

• [6] Hereditary sensory neuropathies (HSNs) are rare disorders characterized by progressive distal sensory loss, predominantly affecting the lower limbs.
• [8] Differential diagnosis includes the other hereditary sensory and autonomic neuropathies (HSAN), especially HSAN II, as well as diabetic foot.
• [9] We describe the follow-up of a 29-year-old man diagnosed with hereditary sensory and autonomic neuropathy type II, including the different complications that may arise.