[Use of 4-methylumbelliferryl-alpha-L-iduronide and 4-trifluoromethylumbelliferryl-alpha-L-iduronide for detecting alpha-L-iduronidase deficiencies in human tissue and for rapid prenatal diagnosis of Hurler disease].

Activity of alpha-L-iduronidase was studied in leukocytes of healthy persons, of patients with Hurler disease and of heterozygous carriers of the disease where 4-methylumbelliferyl-alpha-L-iduronide and 4-trifluoromethylumbelliferyl-alpha-L-iduronide were used as substrates. 4-Trifluoromethylumbelliferyl-alpha-L-iduronide proved to be also a specific substrate of alpha-L-iduronidase and enabled to detect the enzyme deficiency in patients with Hurler disease as well as a decrease of the enzymatic activity in heterozygous carriers of the disease. Using these two substrates prenatal diagnosis of Hurler disease was carried out in fetus which exhibited absence of the enzymatic activity in cell culture from amniotic fluid. The diagnosis was corroborated after analysis of alpha-L-iduronidase activity in liver and kidney tissues of the fetus. 4-Trifluoromethylumbelliferyl-alpha-L-iduronide was very effective in express detection of alpha-L-iduronidase deficiency immediately in tissue slices as well as in placenta which is of importance in prenatal diagnosis of Hurler disease.