Optic Atrophy in a Patient With Atypical Pantothenate Kinase-Associated Neurodegeneration.

Pantothenate kinase-associated neurodegeneration (PKAN) is an autosomal recessive neurodegeneration with brain iron accumulation and characterized by extrapyramidal signs, vision loss, and intellectual decline. PKAN is caused by mutations in the PANK2 gene, which codes for a mitochondrial enzyme that phosphorylates vitamin B5 in the first reaction of the coenzyme A biosynthetic pathway. Visual failure in this disorder is typically due to pigmentary retinopathy. Yet our patient, a 13-year-old girl with PKAN, developed bilateral optic atrophy and the appearance of the retina and electroretinography were normal. Optic atrophy is a rare finding in patients with PKAN. It is important for the clinician to consider PKAN in the differential diagnosis of patients presenting with signs of extrapyramidal dysfunction, cognitive decline, and vision loss because of optic atrophy.