ABSTRACT
Isoenzyme 5 occurring in lysosomelike bodies, cytoplasmic vesicles, and Golgi apparatus saccules of B-lymphocytes in hairy cell leukemia. The presence of this enzyme may be of diagnostic value.
TAY-SACHS DISEASE
A lipid storage disorder inherited as an autosomally recessive trait. Deficiency of hexosaminidase A results in the accumulation of ganglioside GM2 within neural tissues. As with several similar disorders, it is prevalent in Ashkenazi Jews (incidence 1:2000). Presentation is within 6 months of birth, with rapidly progressive neurological deficit, mental retardation, deafness, blindness (cherry red spot at macula), and fits. Ultimately, a vegetative state ensues, followed shortly by death. Diagnosis is made by tissue biopsy or enzyme estimation in leukocytes or tissue fibroblasts.
