Clinical diversity, diagnosis and treatment of hereditary amyloid neuropathy

Abstract

Hereditary amyloid neuropathy includes hereditary ATTR, hereditary AGel, hereditary AApoAI, and hereditary Aβ2M amyloidosis. Among these diseases, hereditary ATTR is the most common type of amyloidosis caused by mutation in the transthyretin (TTR) gene. Hereditary ATTR amyloidosis is a life-threatening, multi-symptom, gain-of-toxic-function disease that may present with peripheral neuropathy, autonomic neuropathy, cardiomyopathy, ophthalmopathy, and/or leptomeningeal amyloidosis. In addition to the clinical symptoms described above, proven amyloid deposition in biopsy specimens and identification of disease-causing mutations in the TTR gene are necessary to establish the diagnosis. Deposition of amyloid in tissue can be demonstrated by Congo red staining of biopsy materials. Liver transplantation has been shown to be an effective therapeutic strategy for ameliorating hereditary ATTR amyloidosis, however, large numbers of patients are not suitable transplant candidates because of their age and/or advanced disease status. Recently, the clinical effects of TTR tetramer stabilizers, tafamidis and diflunisal, were demonstrated in randomised clinical trials, and tafamidis has been approved for the treatment of hereditary ATTR amyloidosis in European countries and in Japan. With the availability of disease-modifying therapies, early diagnosis and therapy become increasingly important in ATTR amyloidosis.