Table 2.

The SCN9A is a Gene Which Belongs to a Gene Family That is Involved in the Development of Sodium Channels

Status	Study Title	Conditions	Interventions	Phase	Sponsor/Collaborators	Locations
Completed Has results	The impact of SCN9A gene polymorphism on individual pain perception in the general population	Pain Surgery			Xianwei Zhang Huazhong University of Science and Technology	Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan, Hubei, China
Recruiting	fMRI-study in patients with small fiber neuropathy	Small fiber neuropathy	Diagnostic test: functional MRI		Academisch Ziekenhuis Maastricht Harvard University	Maastricht University Medical Center Maastricht, Netherlands
Completed	The impact of the SCN9A gene polymorphism on postoperative pain	Pain, postoperative Pregnancy	Procedure: cesarean section Drug: Opioid Tramadol		Tokat Gaziosmanpasa University	Gaziosmanpasa University Medical School Hospital Tokat, Turkey
Completed	Safety and tolerability of lacosamide in patients with gain-of-function Nav1.7 mutations related small fiber neuropathy	Small fiber neuropathy	Drug: Lacosamide Drug: Placebo	Phase 3	Academisch Ziekenhuis Maastricht	Maastricht University Medical Center Maastricht, Netherlands
Active, not recruiting	Evaluation and risk assessment for persistent postsurgical pain after breast surgery	Breast cancer Chronic pain Acute pain Depression, anxiety	Other: Questionnaires Other: Mechanical temporal summation assessment Other: Pain threshold assessment		KK Women’s and Children’s Hospital Duke University	Duke University Medical Center Durham, North Carolina, United States KK Women’s and Children’s Hospital Singapore, Singapore
Unknown †	Painful channelopathies study	Erythromelalgia Pain insensitivity, congenital Hereditary sensory and autonomic neuropathies Chronic pain	Other: Observation		King’s College London University of Oxford Neuroscience Technologies S.L.P	Nuffield Department of Clinical Neurosciences Oxford, Oxfordshire, United Kingdom

Notes: The positively charged sodium ions are transmitted through these channels generating and transmitting electrical signals. The SCN9A gene is involved in the making of the alpha subunit of its protein expression which assembles into the sodium channel called Nav1.7. Nav1.7 is found in key locations within the peripheral nervous system and is involved in the transmission of pain signals. There is presently six human clinical trials studies that are associated with the understanding of SCN9A that are listed on http://www.clinicaltrials.gov as of December 2022. Of the several studies listed, only one indicated a human clinical phase III study completion. That study looked at small fiber neuropathy treated by the therapeutics lacosamide. Lacosamide is a therapeutic that is used to control seizure, namely partial onset seizures, in both adults and children from the age of one month and older. The results were in conclusion. Therefore, there is a presently no Food and Drug Administration (FDA) approval of a small molecule that can be used to treat chronic pain no matter the source of pain. The small lack of therapeutic studies could indicate the challenges of a moving a small molecule through human clinical trials targeting SCN9A. Yet, there is significant evidence that the targeting of the gene has the potential bring to bear hope to millions that suffering from chronic pain. A success treatment targeting SCN9A could be the answer to the opioid crisis by presenting a viable therapeutic alternative.