A novel ARSA gene mutation c.302delG in a Chinese patient with metachromatic leukodystrophy

Metachromatic leukodystrophy (MLD) is an autosomal recessive lysosomal storage disorder mainly caused by the arysulfatase A (ARSA) gene mutations, which results in ARSA activity deficient to accumulate sulfatide in the oligodendrocytes and in the Schwann cells. On the basis of the age of onset, MLD is characterized by three clinical subtypes: late infantile, juvenile, and adult. In this manuscript we report a novel ARSA gene mutation c.302delG in a Chinese late infantile form MLD patient. The frameshift mutation c.302delG changes translated amino acid sequence and creates a premature stop codon in exon 2 at residue 107 (G101Afs*7) according to Mutation Taster Database analysis. Moreover, the mutation c.302delG also damages the protein structure in comparison to that of wild type ARSA protein through SWISS-MODEL. Combined with the patient's typical late infantile presentation, we speculate it may be the cause of MLD.