Vitreous involvement as initial presentation of hereditary transthyretin amyloidosis related to the rare TTR Ile107Met (p.Ile127Met) pathogenic variant.

ABSTRACT

BACKGROUND: Hereditary transthyretin amyloidosis (ATTR) is a multisystemic disease with autosomal dominant inheritance, characterized by the deposition of amyloid-insoluble proteins. We describe a case of vitreous amyloidosis as the initial presentation of ATTRv amyloidosis resulting from the rare Ile107Met (p.Ile127Met) pathogenic variant. MATERIALS AND METHODS: Ophthalmic examination, multimodal imaging, vitreous biopsy, and genetic testing were performed to confirm the diagnosis. RESULTS: A 44-year-old woman presented with blurred vision and floaters in both eyes (OU) for 1 year. The vitreous showed numerous strand-like opacities that were predominant in the anterior vitreous of OU. After a systemic workup and excluding malignancy, vitreous amyloidosis was suspected. Pars plana vitrectomy (PPV) of the left eye (OS) was performed, and a vitreous sample was obtained for histopathology. Homogeneous eosinophilic granular and filamentous deposits that showed an orange-red color with Congo red special stain were observed in the vitreous material, confirming vitreous amyloidosis. A PPV for the right eye (OD) was performed, and her vision at discharge was 20/20 OU. Systemic evaluation discarded neurologic or other systemic manifestations; however, there was familiar involvement in three generations with neurologic symptomatology, confirming an autosomal dominant inheritance pattern. Molecular analysis of the TTR gene showed a likely pathogenic variant Ile107Met (p.Ile127Met). CONCLUSIONS: The present report describes a patient with ATTRv amyloidosis with initial vitreous involvement and the pathogenic variant Ile107Met (p.Ile127Met). It is important to consider vitreous amyloidosis as part of the non-malignant, non-infectious uveitis masquerade syndromes.