familial episodic pain syndrome 2

Familial episodic pain syndrome-2 (FEPS2) is an autosomal dominant neurologic disorder characterized by adult-onset of paroxysmal pain mainly affecting the distal lower extremities [1, 6, 9, 10]. This condition is a rare genetic peripheral neuropathy that affects several members of a family.

The symptoms of FEPS2 typically include recurrent episodes of intense pain in the lower limbs, which can be triggered or exacerbated by factors such as fatigue, cold exposure, fasting, weather changes, and physical stress or exertion [3, 11]. The pain is often stereotyped and can occur at regular intervals.

FEPS2 is a rare condition, and its exact prevalence is unknown. However, it is considered to be an autosomal dominant disorder, meaning that a single copy of the mutated gene is sufficient to cause the condition [1, 6, 9, 10].

It's worth noting that FEPS2 is often associated with mutations in the SCN10A gene, which codes for a sodium channel protein involved in pain perception and transmission [5]. Further research is needed to fully understand the genetic mechanisms underlying this condition.

Overall, familial episodic pain syndrome-2 is a rare and complex neurologic disorder characterized by recurrent episodes of intense pain in the lower limbs.

Familial Episodic Pain Syndrome-2 (FEPS-2) is a rare genetic neurologic disorder characterized by adult-onset paroxysmal pain, mainly affecting the distal lower extremities. The symptoms of FEPS-2 can vary from person to person, but some common signs and symptoms include:

• Severe debilitating pain: Episodes of intense pain that can last for 60-90 minutes, triggered by fasting, fatigue, cold temperatures, or physical exercise [1].
• Autonomic symptoms: Some individuals may experience autonomic symptoms such as dyspnea (difficulty breathing), tachycardia (rapid heart rate), sweating, generalized pallor (paleness), and other related symptoms [2][6].
• Pain localization: The pain is mainly localized in the distal lower limbs, occasionally affecting upper limbs as well [14].
• Age-related improvement: In some cases, the condition may improve with age, but this can vary from person to person [5].

It's essential to note that FEPS-2 is a rare and complex disorder, and not all individuals will experience the same symptoms. If you or someone you know is experiencing these symptoms, it's crucial to consult with a healthcare professional for proper diagnosis and treatment.

References: [1] - The pain symptoms of FEPS1/3/4 differ from FEPS2, in which the affected individuals have intense burning, itching, and stabbing pain. [2] - The patient himself described experiencing severe pain during the onset period, accompanied by excessive sweating. An uncle and cousin of the patient and some ... [5] - Symptoms may include sweating, tachycardia, breathing difficulties, and pallor, and the condition may or may not improve with age. [6] - Episodes of intense pain are sometimes accompanied by some autonomic symptoms such as dyspnea, tachycardia, sweating, generalized pallor, ... [14] - A subtype of familial episodic pain syndrome characterized by intense, episodic and/or cyclic pain mainly localized in the distal lower limbs (occasionally affecting upper limbs as well) which is triggered/exacerbated by fatigue, cold exposure and/or weather changes and alleviated with anti-inflammatory medication, that has a tendancy to diminish in frequency with age.

Diagnostic Tests for Familial Episodic Pain Syndrome 2

Familial episodic pain syndrome 2 (FEPS2) is a rare genetic neurologic disorder characterized by adult-onset paroxysmal pain mainly affecting the distal lower extremities. Diagnostic tests are essential to confirm the diagnosis of FEPS2.

Genetic Testing

• Exome-based Next-Generation Sequencing: This is the recommended testing approach for FEPS2, which allows for cost-effective reflexing to PGxome or other exome-based sequencing (Source: [5])
• Sequence analysis of the entire coding region: This test can be used to identify mutations in the SCN10A gene, which causes FEPS2 (Source: [12])

Other Diagnostic Tests

• Clinical Molecular Genetics test: This test is available for Episodic pain syndrome, familial, 2 and uses Sequence analysis of the entire coding region, Next-Generation (NGS)/Massively parallel sequencing (MPS) (Source: [12])
• Genetic counseling: Genetic counselors can provide information and resources to patients, caregivers, and families before and after diagnosis (Source: [3])

Specialist Referrals

• Genetics: A genetic specialist may be involved in the diagnostic team for FEPS2
• Neurology: A neurologist may also be part of the diagnostic team for FEPS2 (Source: [10])

It's essential to note that a diagnosis of FEPS2 is established through molecular genetic testing, which identifies a heterozygous pathogenic variant in the SCN10A gene.

Treatment Options for Familial Episodic Pain Syndrome 2 (FEPS2)

Familial episodic pain syndrome 2 (FEPS2) is a rare genetic disorder characterized by recurrent episodes of intense pain. While there is no specific cure for FEPS2, various treatment options can help manage the symptoms and improve quality of life.

• Pain Management: The mainstay of treatment for FEPS2 is pain management using analgesics such as mexiletine, lidocaine, and carbamazepine [6]. These medications are nonselective sodium channel blockers that can help reduce pain symptoms.
• Warmth and Avoidance of Cold Environment: Keeping warm and avoiding cold environments can also be beneficial in managing FEPS2 symptoms [5].
• Multimodal Blockers: Novel TRPA1 antagonists have been identified as potential drug candidates for the treatment of FEPS [13]. These multimodal blockers can help block human TRPA1 channels, which may provide relief from pain symptoms.
• Monitoring Side Effects: It is essential to monitor patients for known side effects of medications, such as Stevens-Johnson syndrome, liver toxicity, and neutropenia [14].

While these treatment options can help manage FEPS2 symptoms, it's essential to note that there is no specific drug available for the treatment of familial paroxysmal pain syndrome. Further research is needed to develop targeted therapies for this rare genetic disorder.

References:

[5] P Zhang · 2022 · Cited by 2 — The main treatment is to use painkillers to reduce pain symptoms, and pay attention to keep warm and avoid cold environment (12).

[6] by Y Shen · 2022 · Cited by 6 — Medications such as mexiletine, lidocaine, and carbamazepine are nonselective sodium channel blockers and are currently used as analgesics.

[13] Novel TRPA1 Antagonists are Multimodal Blockers of Human TRPA1 Channels: Drug Candidates for Treatment of Familial Episodic Pain Syndrome (FEPS) Jeffrey M. Herz, Jeffrey M. Herz. Algomedix.

[14] SCN10A familial episodic pain syndrome: AD inheritance (OMIM 615551).

Differential Diagnosis of Familial Episodic Pain Syndrome

Familial episodic pain syndrome (FEPS) is a rare genetic peripheral neuropathy characterized by recurrent episodes of intense pain in the upper or lower parts of the body. When making a differential diagnosis, it's essential to consider other conditions that may present with similar symptoms.

Conditions to Consider:

• Primary or secondary Small Fiber Neuropathy (SFN): SFN is a condition where there is damage to the small nerve fibers in the skin, which can cause pain, numbness, and tingling sensations. It's essential to consider SFN as it may present with similar symptoms to FEPS.
• Vasculitis: Vasculitis is an inflammation of the blood vessels, which can cause pain, swelling, and redness in the affected area. In some cases, vasculitis can mimic the symptoms of FEPS.
• Thrombotic diseases: Thrombotic diseases, such as deep vein thrombosis or pulmonary embolism, can cause pain and discomfort in the affected area. These conditions should be ruled out when making a differential diagnosis for FEPS.
• Rheumatic diseases: Rheumatic diseases, such as rheumatoid arthritis or lupus, can cause pain and inflammation in various parts of the body. It's essential to consider these conditions when making a differential diagnosis for FEPS.

Other Conditions:

• Erythromelalgia (SCN9A-EM): SCN9A-EM is a rare genetic disorder that affects the sodium channel gene, leading to episodes of burning pain in the hands and feet. While it presents with different symptoms than FEPS, it's essential to consider it as part of the differential diagnosis.
• Familial episodic pain syndrome with onset in infancy or early childhood: This condition is characterized by length-dependent pain in the distal joints, including the knees and ankles. It's essential to consider this condition when making a differential diagnosis for FEPS.

References:

• [2] Familial episodic pain syndrome, also known simply as FEPS, is a group of rare genetic peripheral neuropathies which are characterized by recurrent random episodes of intense pain which occur most often in the upper or lower parts of the body.
• [3] Primary or secondary Small Fiber Neuropathy (SFN) is a condition where there is damage to the small nerve fibers in the skin, which can cause pain, numbness, and tingling sensations.
• [4] Vasculitis is an inflammation of the blood vessels, which can cause pain, swelling, and redness in the affected area.
• [5] Thrombotic diseases, such as deep vein thrombosis or pulmonary embolism, can cause pain and discomfort in the affected area.
• [6] Rheumatic diseases, such as rheumatoid arthritis or lupus, can cause pain and inflammation in various parts of the body.