MRI findings are consistent with metachromatic leukodystrophy (MLD). Confirmatory genetic testing showed two pathogenic mutations in the ARSA gene as well as two copies of ARSA variants associated with reduced enzyme activity, compatible with the diagnosis of MLD.

Metachromatic leukodystrophy is a rare lysosomal storage disorder related to decreased arylsulfatase A (ARSA) activity. This patient presents with the juvenile form of the disease. There are also late infantile and adult forms. A bone marrow transplant can be used to delay the progression of the disease. Patients eventually have neurologic and cognitive impairment and early death.