SLC38A8 is an electrogenic sodium-dependent amino acid transporter that preferentially transports L-glutamine, L-alanine, L-histidine, L-aspartate, and L-arginine across cell membranes 1. The transporter facilitates glutamine uptake in neurons, though its complete transport mechanism and stoichiometry require further elucidation. SLC38A8 plays a critical role in visual pathway development independent of melanin biosynthesis. Biallelic mutations in SLC38A8 cause foveal hypoplasia (FH)—arrested foveal development—and optic nerve misrouting without albinism 1. SLC38A8 variants account for approximately 6.8% of genetic FH cases and represent the second most common non-albinism cause of congenital nystagmus with FH 23. Most pathogenic variants are missense mutations located in transmembrane domains, with 66% of patients presenting severe grade 4 FH and absence of photoreceptor specialization 42. Beyond ophthalmology, SLC38A8-mediated aspartate transport is hijacked by picornaviruses (FMDV, EV71, SVV) to enhance viral replication through mTORC1 pathway activation, suggesting a broader metabolic role 5. Genetic diagnosis of SLC38A8 mutations is clinically essential for accurate prognostication, family counseling, and distinguishing FH etiology from other developmental causes.