Influence of Age and Type of First Symptoms on Disease Progression in Metachromatic Leukodystrophy

Background: Metachromatic leukodystrophy (MLD) is a lysosomal storage disorder due to ARSA-Gene mutations leading to deficiency of arylsulfatase A (ARSA). The disease results in progressive loss of motor, cognitive and behavioural function. While disease course in the late-infantile form shows rapid and uniform decline, it is more variable and protracted in later-onset forms. Aim of the study was to compare disease progression between the different onset forms and to investigate the influence of type of first symptoms on the natural course.