Abstract
Purpose: To report a case of 16-month-old boy with a novel variant TSPAN12 gene-presenting as unilateral myopia, pediatric cataract, and heterochromia in a patient with familial exudative vitreoretinopathy. Observation: A 16-month-old otherwise healthy boy was referred to Boston Children's Hospital for evaluation of strabismus. Ocular examination revealed intermittent esotropia, left hypotropia, and limited left eye elevation in both adduction and abduction. Full cycloplegic hyperopic correction of +3.50 diopters (D) over both eyes was given to the patient. Over several months, refraction of the right eye showed progressive myopia (-6.00 D) with new onset iris heterochromia. Fundus examination showed there was a large area of chorioretinal atrophy with abrupt ending of the blood vessels; anterior to the ora serrata there were diffuse vitreous bands and veils that reached the lens anteriorly in direct contact with the lenticular opacity. A novel heterozygous nonsense likely pathogenic variant was identified in the TSPAN12 gene (NM_012338.3) c.315T>A (p.Cys105Ter) confirming the diagnosis of FEVR. Conclusion and importance: Asymmetric FEVR rarely present with unilateral axial myopia however association with acquired heterochromia and cataract has never been reported. We report a case of FEVR caused by a novel TSPAN12 likely pathogenic nonsense variant presenting as unilateral progressive myopia, acquired heterochromia, and pediatric cataract.