Prenatal diagnosis of cystic fibrosis: false negative result with the 4-methylumbelliferyl-p-guanidinobenzoate assay for proteases in amniotic fluid.

Abstract

The promising method for the prenatal detection of cystic fibrosis (CF), developed by Naldler's group [6,7], has recently attracted considerable interest but there is a lack of confirmatory reports from other laboratories. We have established the assay for methylumbelliferyl-guanidinobenzoatereactive proteases (MUGB assay) and used it, together with isoelectric focusing and gel filtration, to screen retrospectively 84 second and third trimester amniotic fluids, one of which was known to be from a CF pregnancy.