NN′-Diacetylchitobiase activity in Tay–Sachs disease and Sandhoff's disease

In Tay–Sachs disease and Sandhoff's disease respectively, one of the N-acetyl-β-hexosaminidases (form A) or both (forms A and B) are absent, but glycosaminoglycans containing N-acetylhexosamines are not accumulated. The presence of NN′-diacetylchitobiase in livers from patients with these diseases raises the possibility that this new enzyme is involved in the metabolism of glycosaminoglycans rather than the enzymes previously described.