The diagnostic value of sural nerve biopsy in metachromatic leucodystrophy and other conditions with low leucocyte arylsulphatase A activities.

The value of sural nerve biopsy in the diagnosis of metachromatic leucodystrophy (MLD) was studied in 9 MLD-patients and 4 other patients with low arylsulphatase A (ASA)-activities in the leucocytes. In 7 patients (5 of them suffering from MLD) adequate interpretation of low ASA-activity was impossible, either because one of the parents also had low ADA-activity or because the obligatory information about the ASA-activity of the parents could not be obtained. In these cases sural nerve biopsy provided essential diagnostic information, correcting one false negative and two false positive diagnoses of clinical MLD.