Ophtalmologic changes in transthyretin familial amyloid polyneuropathy (ATTR-FAP)

Background Familial amyloid polyneuropathy (FAP) is an inherited disorder with autosomal dominant transmission and multiple phenotypes, characterized by systemic accumulation of amyloid fibrils. The most common type of FAP is related to a mutant transthyretin (TTR). TTR is mainly synthesized in the liver, but few amount of TTR is produced in the eye, namely in retinal pigment epithelium, which explains the continuous intra-ocular amyloid deposition observed in patients submitted to liver transplantation. The incidence of ophthalmic manifestations related to FAP depends on mutation involved, geographical area of patient and time of evolution of the disease. More than 100 mutations of TTR have been described but the most frequent in Portugal is TTR Val30Met. Even the same population with the same mutation can present significant clinical variability. TTR Met30Val FAP patients have different phenotypes according to their age at onset of the disease.