Adult metachromatic leukodystrophy. Arylsulphatase-A values in four generations of one family and some reflections about the genetics.

The authors describe an investigation of Adult Metachromatic Leukodystrophy in a Dutch family, of which two persons were affected. The studies of leukocyte arylsulphatase-A activity were made in 47 members of 4 generations of the same family. The propositus, a 30-year old man, showed a conspicious organic brain syndrome, that progressed in two years to a complete dementia. His leukocyte, liver and kidney arylsulphatase-A activities (ASA) were very low; leukocyte-ASA activity increased after aceto-salicylate. His brother had died at 34 years, after a progressive debelitating neuropsychiatric illness of eight years; postmortem metachromatic leukodystrophy was diagnosed. In all living family members, urine and leukocyte arylsulphatase-A activities were determined. The findings are discussed in relation to the genetics and pathogenesis of this adult form of metachromatic leukodystrophy. Allelic heterozygoty is proposed as inheritance model in this family. Suggestions for further research are made.