Elevated beta-N-acetylhexosaminidase activity in focal dystonia fibroblasts

Specific activities of beta-D-hexosaminidase, alpha-D-mannosidase, beta-D-g alactosidase and beta-D-glucuronidase were determined in fibroblasts of pat ients with writer's cramp and torticollis. These diseases show degenerative neurological disorders similar to those observed in lysosomal diseases. He xosaminidase specific activities, determined using 4-methylumbelliferyl-bet a-N-acetylglucopyranoside and 4-methylumbelliferyl-beta-N-acetylglucopyrano side-6-sulphate as substrates, were significantly higher in the fibroblasts of patients than in controls. No significant differences were observed in the specific activities of the other lysosomal enzymes. The increased hexos aminidase specific activities in torticollis and writer's cramp may be addi tional markers for these diseases. (C) 1999 Elsevier Science B.V. All right s reserved.