[Transthyretin Arg-83 mutation in vitreous amyloidosis]

Vitreous amyloidosis is a rare condition that mainly occurs in Familial Amyloidotic Polyneuropathy (FAP). In some cases, it may be the only symptom without systemic disorders. One case of familial vitreous amyloidosis was reported here, with white, wispy opacities in vitreous cavity in both eyes. Pars plana vitrectomy and histopathological examination of the vitreous specimens were performed. The vitreous specimens showed typical microscopic features of amyloidosis with Congo red stain and non-branching fibrils on a transmission electron microscope. Transthyretin (TTR) gene was amplified with DNA isolated from the peripheral blood cells. Bi-directional sequencing of exon 3 showed a single base-pair substitution, which results in an amino acid substitution at position83, glycine to arginine (TTR Arg-83). TTR Arg-83 may be a new pathologic mutation in vitreous amyloidosis.