Transthyretin-Related Familial Amyloidosis Polyneuropathy with Spinal Cord Damage: A Case Report.

Introduction: Transthyretin protein-related familial amyloidosis polyneuropathy (TTR-FAP) is an autosomal dominant genetic disease caused by mutations in the TTR gene. The disease is characterized primarily by peripheral and autonomic nerve damage. Disease progression is associated with frequent involvement of the heart, lungs, kidneys, eyes, and other organs. The most common TTR mutation is c.148G>A (p.Val50Met), although the FAP resulting from the mutation rarely involves the spinal cord. Patient Concerns: A 68-year-old man was diagnosed with the TTR c.148G>A (p.Val50Met) mutation by ultrasound, pathological, and genetic analyses. He presented with a late-onset, complicated spinal cord injury. The diagnostic process was tortuous, and despite the administration of regular treatment (conventional drugs, cardiac pacemaker, and the specific drug clofenadifen), the patient died. Interventions: To confirm TTR-FAP, ultrasound, MRI, pathological, and genetic tests were performed. Outcomes: The patient ultimately died of heart failure 7.5 years after the initial onset of symptoms. Conclusion: The patient presented with unusual symptoms of spinal cord injury, and despite a long and arduous diagnostic process and administration of standard treatment for over seven years, the outcome was poor. It is thus recommended that clinicians pay attention to the identification of rare diseases with timely imaging, pathological, and genetic testing, to avoid poor outcomes.