Familial Dysautonomia
Section outline
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Familial dysautonomia (FD) is a rare autosomal recessive disorder caused by pathogenic variants in the ELP1 gene, affecting sensory and autonomic neurons. Ocular manifestations are common but frequently underrecognized, leading to delayed diagnosis. We report a patient presenting with progressive, painless bilateral vision loss. Visual acuity and color vision were markedly reduced, with sluggish pupillary responses and bilateral optic atrophy. The initial differential diagnosis included compressive, vascular, inflammatory, toxic, and hereditary optic neuropathies. Genetic testing revealed compound heterozygous pathogenic variants in ELP1, confirming FD. Ophthalmic evaluation demonstrated a characteristic optic neuropathy with selective papillomacular bundle involvement, thinning of the macular ganglion cell complex and retinal nerve fiber layer, and central visual field defects, consistent with a mitochondrial-like optic neuropathy. Anterior segment findings included reduced corneal sensitivity, decreased tear secretion, and neurotrophic keratopathy, explaining the absence of pain and emotional tearing. This case highlights the eye as a critical diagnostic window in FD. Recognition of painless visual loss combined with distinctive optic nerve and corneal findings should prompt consideration of FD and genetic testing, particularly given emerging disease-modifying therapies targeting ELP1 expression.
Presentation Date: 01/08/2026
Issue Date: 03/20/2026
