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

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.