脳リピドーシス

酵素学的立場から

抄録

Recent advances in the biochemical research of sphingolipidoses were reviewed, with special reference to various types of gangliosidoses and Krabbe's globoid cell leukodystrophy.
A special type of G_m2-gangliosidosis, Sandhoff's disease, was recently found, which is characterized by a deficiency of total hexosaminidase activity, with accumulation of globoside in visceral organs in addition to generalized G_m2-ganglioside storage. Its molecular and genetic basis of enzyme deficiency in relation to classical Tay-Sachs disease is not known.
β-Galactosidase deficiency is a common characteristic biochemical abnormality in Krabbe's disease, lactosylceramidosis and two clinical types of G_m1-gangliosidosis. The former two diseases can be diagnosed by deficiency of specific enzymes, galactocerebrosidase and ceramide lactoside β-galactosidase respecti vely, whereas the latter presents an extremely low β-galactosidase activity also for synthetic substrates. At present the fundamental biochemical difference between two types of G_M1-gangliosidosis is notestablished yet. More information of the nature on β-galactosidase deficiency is necessary for the understanding of these biochemically interrelated diseases.
Enzyme assay methods are now applied for the diagnosis of almost every sphingolipidosis at any stage, including the preclinical and the intrauterine periods, by the use of clinically available materials such as peripheral blood, cultured skin fibroblasts or amniotic fluid cells, although many basic biochemical problems still remain to be solved in future.