Type IV Familial Amyloid Polyneuropathy (FAP) is a rare and inherited form of amyloidosis, which is a group of disorders characterized by the buildup of abnormal proteins called amyloid in various organs and tissues of the body. FAP specifically affects the peripheral nervous system, leading to polyneuropathy.
FAP is caused by mutations in the transthyretin (TTR) gene, which produces a protein called transthyretin. These mutations cause the formation of abnormal transthyretin proteins that can misfold and aggregate, leading to the deposition of amyloid fibrils in nerves of the peripheral nervous system. Over time, this accumulation can cause progressive damage to the nerves, resulting in sensory disturbances, motor deficits, and autonomic dysfunction.
Typical symptoms of FAP include numbness, tingling, and pain in the extremities, muscle weakness, loss of coordination, and gastrointestinal disturbances. The severity and progression of the disease can vary among individuals depending on the specific TTR mutation and other factors.
Diagnostic approaches for FAP may include genetic testing to identify the specific TTR mutation, nerve biopsies to observe the presence of amyloid deposits, and imaging techniques to assess nerve damage. Treatment options may include liver transplantation, which can decrease the production of the abnormal protein, and novel drug therapies that aim to stabilize the transthyretin protein or prevent the formation of amyloid fibrils.
Type IV Familial Amyloid Polyneuropathy is a progressive condition that can significantly impact an individual's quality of life and necessitate ongoing medical management and support.
