Immunochemical Studies of Cerebroside Sulphatase

Abstract

Metachromatic leucodystophy is an autosomal recessive lysosomal disorder of cerebroside sulphate metabolism due to an inborn deficiency of arylsulphatase A, cerebroside sulphatase. Although a detailed clinical and pathological description of the disease was given by Scholz (1925), the enzyme defect was not elucidated until 1963 (Austin et at., 1963). Since that time a variety of clinical variants have presented, the late infantile, juvenile and adult forms being the most common. It has been suggested (Farrell et at., 1979) that the late infantile form is qualitatively different from the others and that non-allelic mutations are involved. Complicating the picture are reports in the literature of metachromatic leucodystrophy without an associated enzyme deficiency and of enzyme deficiencies with no apparent clinical manifestations. In the former case, it has been shown that an associated activator protein is missing but the latter case, often termed a pseudo-deficiency, is still not completely resolved. Recent cases seen at the Royal Manchester Children’s Hospital, where low levels of arylsulphatase A are accompanied by non-progressive mental retardation, complicate the situation further.