Lysosome enzyme pseudodeficiency.

Inherited deficiency of lysosomal hydrolase often displays different clinic al features. However, a greatly reduced enzyme activity may be observed in healthy individuals. This pseudo-deficiency concernes at least nine lysosom al hydrolases. When a deficiency has been proved, the presence of mutations known to cause pseudodeficiencies must be searched, above all in Tay-Sachs disease and me tachromatic leukodystrophy.