Longitudinal Evolution of Neuroimaging Findings in Fucosidosis: Expanding the Neuroradiologic Spectrum

Fucosidosis is an exceptionally rare autosomal recessive lysosomal storage disorder caused by deficiency of α-L-fucosidase due to pathogenic variants in the FUCA1 gene. Neurologic involvement is prominent, and magnetic resonance imaging (MRI) frequently provides early diagnostic clues through characteristic white matter and deep gray matter abnormalities. We present an 18-year-old female with genetically confirmed fucosidosis and longitudinal neuroimaging spanning 15 years. Initial MRI at 23 months of age demonstrated confluent symmetric supratentorial white matter T2 hyperintensity and subtle medial medullary lamina hyperintensity within the globi pallidi. Follow-up studies demonstrated progressive basal ganglia involvement with evolving T1 and T2 shortening, and susceptibility changes consistent with mineralization extending to the substantia nigra and red nuclei. Detailed longitudinal evolution of neuroimaging findings, particularly progressive deep gray matter mineralization, has been sparsely described in fucosidosis. This case expands the described neuroradiologic spectrum of fucosidosis by highlighting the temporal evolution of white matter and deep gray matter abnormalities, and underscores the value of MRI pattern recognition over time in prompting consideration of rare lysosomal storage disorders and guiding targeted metabolic and genetic evaluation.