Congenital microcephaly and bilateral chorioretinal atrophy associated with a KIF11 nonsense variant

Purpose: Microcephaly and chorioretinal atrophy are recognized clinical features associated with variants in kinesin family member 11 (KIF11), yet the phenotypic spectrum continues to expand as additional pathogenic variants are identified. We report a 17-year-old male with a history of microcephaly who presented for evaluation of bilateral chorioretinal abnormalities.Methods: A single case was retrospectively reviewed.Results: Examination revealed well-circumscribed inferior chorioretinal atrophic lesions measuring four- to five-disc diameters in both eyes, with preserved macular architecture and normal retinal vasculature. Optical coherence tomography demonstrated marked outer retinal and choroidal thinning with excavation and loss of the ellipsoid zone. Fundus autofluorescence showed sharply demarcated hypoautofluorescent areas corresponding to the lesions. Serologic testing for Toxoplasma gondii IgG and IgM was negative. Targeted panel next-generation sequencing identified a heterozygous pathogenic KIF11 nonsense variant (c.2449C > T, p. Gln817*) and a heterozygous MAPKAPK3 variant of uncertain significance. Visual acuity and multimodal imaging remained stable over 30 months of follow-up.Conclusions: This case highlights the phenotypic spectrum of KIF11-associated retinopathy, illustrating a non-progressive form confined to the inferior fundus. Recognition of this presentation is important, as its appearance could mimic congenital infectious scars. Genetic testing plays a critical role in establishing the diagnosis, guiding systemic evaluation, and informing family counseling.