The Dynamics of a Lipidosis

Metachromatic leukodystrophy (MLD) is the most common inborn error of metabolism affecting the white matter of human brain. In 1958, both Jatzkewitz1and Austin2demonstrated independently that the sulfatide concentration in the central nervous system (CNS) was increased in MLD, and a similar increase of sulfatide in peripheral nerve, kidney, liver, gallbladder, and urine has also been reported.3,4Austin first pointed to an enzymatic defect in MLD by demonstrating a deficiency of arylsulfatase A.5,6In vitro desulfation of sulfatide by a cerebroside sulfatase was first accomplished by Mehl and Jatzkewitz7with a preparation of hog kidney. Subsequently, this enzyme also was isolated from normal human kidney and was found to be lacking in the kidney from a patient with MLD.8Cerebroside sulfatase activity depends upon two components of relatively high molecular weight, one heat-labile, the other heat-stable.8It appears that, in MLD,