Gene dosage effect for beta-glucuronidase (GUSB) in monosomy 7 cells of patients with myeloproliferative disorders.

The demonstration of a gene dosage effect in a neoplastic cell with a specific chromosome abnormality could be helpful in the study of some pathogenetic steps of the malignant growth. We tested the activities of beta-glucuronidase (GUSB), whose gene is mapped on chromosome 7 and of Arylsulphatase A (ARSA) and beta-galactosidase (GLB) as control lysosomal enzymes, whose loci are not assigned to number 7, in a group of 10 patients with myeloproliferative disorders associated with monosomy 7. A significant difference of the levels of activity of GUSB in monosomy 7 cells was found in comparison with two groups of controls, one of healthy subjects, the other of patients with similar disorders without monosomy 7. These results indicate the presence of a gene dosage effect for GUSB.