Highly asymmetric early presentation of FEVR requiring enucleation.

Introduction: Familial exudative vitreoretinopathy (FEVR) is a rare inherited disorder characterized by abnormal retinal vascular development. While it typically presents in childhood, distinguishing it from retinoblastoma in young infants can be challenging, especially in cases with asymmetric and advanced manifestations.

Methods: Case report.

Results: A 2-month-old female with microcephaly and intrauterine growth restriction (IUGR) presented with a left eye intraocular mass involving the entire globe and a flat anterior chamber. MRI showed no calcifications or contrast enhancement typical of retinoblastoma. Intravenous fluorescein angiography showed incomplete vascularization in the contralateral eye with compensatory neovascularization. The left eye was enucleated, and histology demonstrated a dysplastic retina with a retrolental membrane and abnormal vascular proliferations, confirming a diagnosis of FEVR. Genetic testing identified a novel pathogenic p.Gly635* variant, inherited from the mother in whom it was present at 10-20% mosaicism.

Discussion: Variants in cause of CTNNB1-neurodevelopmental disorder, characterized by microcephaly, IUGR, autism spectrum disorder, intellectual disability, and FEVR in 20-40% of cases. Affected children present at an early age and advanced stages of disease. This case highlights that FEVR can have a highly asymmetric and advanced presentation at an early age and must be distinguished from retinoblastoma in the differential diagnosis of leukocoria.