Rapid Prenatal Testing for Human β-Glucuronidase Deficiency (MPS VII)

Prenatal diagnosis for the lysosomal storage disorders is typically achieved by enzymatic analysis of the relevant lysosomal enzyme in cultured amniocytes or chorionic villi. While prenatal diagnosis of some genetic diseases can be done by analysis of pertinent metabolites in amniotic fluid, there are few data regarding prenatal diagnosis of lysosomal disorders by enzyme analysis of amniotic fluid. Prenatal diagnosis by enzyme analysis of amniotic fluid has the potential advantage of providing a more rapid prenatal test result. In this study we describe an assay for the prenatal diagnosis of the mucopolysaccharidosis beta-glucuronidase deficiency (MPS VII; MIM #253220) using amniotic fluid and we confirm its reliability in detecting an affected fetus in an at-risk pregnancy by enzyme analysis of cultured amniocytes and fetal fibroblasts. Because MPS VII is rare and few instances of prenatal diagnosis for this and nearly all other lysosomal disorders have been accomplished by enzyme analysis of amniotic fluid, confirmation of results obtained from enzyme analysis of amniotic fluid should be carried out by enzyme or mutation analysis using cultured amniocytes or chorionic villus specimens.