A deficiency in arylsulfatase A, often due to mutations in the ARSA gene, leads to a condition known as Metachromatic Leukodystrophy (MLD). This lysosomal storage disorder is characterized by the accumulation of sulfatides, causing progressive demyelination in the nervous system. Histologically, this results in a distinct pattern of staining where accumulated sulfatides can be visualized, often appearing as metachromatic granules.
