Alpha-Methylacyl-CoA Racemase (AMACR) Deficiency Presenting with Epilepsy, Cognitive Decline, and Pigmentary Retinopathy

A 66-year-old woman with long-standing epilepsy and progressive cognitive decline presented with bilateral vision loss (best-corrected visual acuity 1.22 logMAR right eye, 1.10 logMAR left eye). Electrodiagnostic testing showed severe rod-cone dysfunction. Fundus autofluorescence revealed bilateral multifocal geographic hypoautofluorescent lesions with hyperautofluorescent borders in a wreath-like pericentral distribution. Optical coherence tomography demonstrated bilateral outer retinal atrophy with ellipsoid zone loss and cystoid macular edema in the left eye. Genetic testing identified a pathogenic AMACR variant (c.154T>C; p.Ser52Pro) and a variant of uncertain significance (c.704C>T; p.Ala235Val). Elevated pristanic acid (152.9 μmol/L) confirmed alpha-methylacyl-CoA racemase (AMACR) deficiency, explaining her neurological disease. Macular edema decreased by 50 μm with topical dorzolamide and a phytanic and pristanic acid-restricted diet, and she reported subjective neurological improvement. Retinal imaging may be the first diagnostic clue to this rare but treatable condition. Ophthalmologists should consider AMACR deficiency in unexplained pigmentary retinopathy with neurological disease.