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

Abstract

Objective. To describe the use of an advanced genetic testing technique, whole exome sequencing, to diagnose a patient and their family with aSCN9Achannelopathy.Setting. Academic tertiary care center.Design. Case report.Case Report. A 61-year-old female with a history of acute facial pain, chronic pain, fibromyalgia, and constipation was found to have a gain of functionSCN9Amutation by whole exome sequencing. This mutation resulted in anSCN9Achannelopathy that is most consistent with a diagnosis of paroxysmal extreme pain disorder. In addition to the patient being diagnosed, four siblings have a clinical diagnosis ofSCN9Achannelopathy as they have consistent symptoms and a sister with a known mutation. For treatment, gabapentin was ineffective and carbamazepine was not tolerated. Nontraditional therapies improved symptoms and constipation resolved with pelvic floor retraining with biofeedback.Conclusion. Patients with a personal and family history of chronic pain may benefit from a referral to Medical Genetics. Pelvic floor retraining with biofeedback should be considered for patients with aSCN9Achannelopathy and constipation.