Diagnosis of classical Morquio's disease: N-acetylgalactosamine 6-sulphate sulphatase activity in cultured fibroblasts, leukocytes, amniotic cells and chorionic villi.
The tritiated disulphated trisaccharide 6-sulpho-N-acetylgalactosamine-glucuronic acid-6-sulpho-N-acetyl-[1-3H]galactosaminitol was prepared from chondroitin 6-sulphate for use as a substrate for N-acetylgalactosamine 6-sulphate sulphatase. The reaction product was separated on ECTEOLA cellulose rather than Dowex 1 X 2. The mean activities of normal fibroblasts, leukocytes and amniotic cells were 8.43, 2.59 and 3.14 nmol h-1 mg protein-1, respectively. Fibroblasts from five patients with classical Morquio's disease (mucopolysaccharidosis IVA; MPSIVA) and one patient with neonatal multiple sulphatase deficiency displayed activities of less than 5% of control mean. Activity in amniotic cells from a pregnancy where the fetus was affected with MPS IVA was 6% of control mean. Activity was also found to be present in normal specimens of chorionic villi (mean value 1.21 nmol h-1 mg protein-1), demonstrating the feasibility of first trimester prenatal diagnosis of MPS IVA by assay of activity in this tissue.
D000653:Amniotic Fluid / Q000166:cytology*; D002478:Cells, Cultured; D002810:Chondroitinases and Chondroitin Lyases / Q000032:analysis*; D002811:Chondroitinsulfatases / Q000032:analysis*; D002824:Chorionic Villi / Q000201:enzymology*; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis*; D005347:Fibroblasts / Q000201:enzymology*; D006801:Humans; D007962:Leukocytes / Q000201:enzymology*; D009085:Mucopolysaccharidosis IV / Q000175:diagnosis* / Q000201:enzymology; D011247:Pregnancy; D011296:Prenatal Diagnosis
D002811:Chondroitinsulfatases; D002810:Chondroitinases and Chondroitin Lyases