Decreased enzyme levels indicate an individual is affected with metachromatic leukodystrophy (MLD). Note that individuals with pseudoarylsulfatase A deficiency can have results in this range, but are otherwise unaffected with MLD.
Abnormal results should be confirmed using ARSU/8777 Arylsulfatase A, Urine. If molecular confirmation is desired, consider molecular genetic testing of the ARSA gene.