Advanced Genetic Testing Comes to the Pain Clinic to Make a Diagnosis of Paroxysmal Extreme Pain Disorder

A Review of the Therapeutic Targeting of SCN9A and Nav1.7 for Pain Relief in Current Human Clinical Trials

Introduction

There is a great need to find alternative treatments for chronic pain which have become a healthcare problem. We discuss current therapeutic targeting Nav1.7.

Areas Covered

Nav1.7 is a sodium ion channel protein that is associated with several human pain genetic syndromes. It has been found that mutations associated with Nav1.7 lead to the loss of the ability to perceive pain in individuals that are otherwise normal. Several therapeutic interventions are presently undergoing preclinical and research using the methodology of damping Nav1.7 expressions as a methodology to decrease the sensation of pain leading to analgesia.

Expert Opinion

It is our strong belief that there is a viable future in the targeting of protein of Nav1.7 for the relief of chronic pain in humans. The review will look at the genomics associated with SCN1A and proteomic of Nav1.7 as a foundation to explain the mechanism of the therapeutic interventions targeting Nav1.7, the human disease that are associated with Nav1.7, and the current development of treatment for chronic pain whether in preclinical or clinical trials targeting Nav1.7 expressions. The development of therapeutic antagonists targeting Nav1.7 could be a viable alternative to the current treatments which have led to the opioid crisis. Therefore, Nav1.7 targeted treatment has a major clinical significance that will have positive consequences as it relates to chronic pain interventions.

Discovery and validation of biomarkers to aid the development of safe and effective pain therapeutics: challenges and opportunities

Pain medication plays an important role in the treatment of acute and chronic pain conditions, but some drugs, opioids in particular, have been overprescribed or prescribed without adequate safeguards, leading to an alarming rise in medication-related overdose deaths. The NIH Helping to End Addiction Long-term (HEAL) Initiative is a trans-agency effort to provide scientific solutions to stem the opioid crisis. One component of the initiative is to support biomarker discovery and rigorous validation in collaboration with industry leaders to accelerate high-quality clinical research into neurotherapeutics and pain. The use of objective biomarkers and clinical trial end points throughout the drug discovery and development process is crucial to help define pathophysiological subsets of pain, evaluate target engagement of new drugs and predict the analgesic efficacy of new drugs. In 2018, the NIH-led Discovery and Validation of Biomarkers to Develop Non-Addictive Therapeutics for Pain workshop convened scientific leaders from academia, industry, government and patient advocacy groups to discuss progress, challenges, gaps and ideas to facilitate the development of biomarkers and end points for pain. The outcomes of this workshop are outlined in this Consensus Statement.

Paroxysmal extreme pain disorder in family with c.3892G > T (p.Val1298Phe) in the SCN9A gene mutation - case report

BACKGROUND

To describe the clinical phenotype of paroxysmal extreme pain disorder, an autosomal dominant condition in four members in one family with the mutation NM_002977.3:c.3892G > T (p.Val1298Phe) in the SCN9A gene. Clinical examinations and details from members of one Polish family were collected, including age at onset, features of attacks, problems between attacks, investigational results, treatments tried, and evolution over time.

CASE PRESENTATION

Twenty two individuals from this family with paroxysmal extreme pain disorder were identified. Seven of them presented clinical manifestation of paroxysmal extreme pain disorder, of which and in four were identified missens mutations in the SCN9A gene (NM_002977.3:c.3892G > T). The onset of the disorder took place in the neonatal period or infancy and persists throughout life. Autonomic manifestations predominate with extreme pain, skin flushing and harlequin colour change were observed in all. Attacks of excruciating deep burning pain often appear in the rectal, or jaw areas, but also diffuse in the body. Attacks are triggered by factors such as: defecation, eating, pressure and emotion. Carbamazepine and other antiepileptic drugs were only partly effective in almost all, but the response was incomplete.

CONCLUSIONS

Paroxysmal extreme pain disorder is a hereditary sodium channelopathy with pain and an autonomic nervous system dysfunction. Paroxysmal extreme pain disorder is rare, so far only 500 cases of both women and men have been described in world literature.

Flushing Disorders Associated with Gastrointestinal Symptoms: Part 2, Systemic Miscellaneous Conditions

Flushing disorders with involvement of the gastrointestinal tract represent a heterogeneous group of conditions. In part 1 of this review series, neuroendocrine tumors (NET), mast cell activation disorders (MCAD), and hyperbasophilia were discussed. In this section we discuss the remaining flushing disorders which primarily or secondarily involve the gastrointestinal tract. This includes dumping syndrome, mesenteric traction syndrome, rosacea, hyperthyroidism and thyroid storm, anaphylaxis, panic disorders, paroxysmal extreme pain disorder, and food, alcohol and medications. With the exception of paroxysmal pain disorders, panic disorders and some medications, these disorders presents with dry flushing. A detailed and comprehensive family, social, medical and surgical history, as well as recognizing the presence of other systemic symptoms are important in distinguishing the different disease that cause flushing with gastrointestinal symptoms.