An abnormal pattern of amniotic fluid microvillar enzymes signalling fetal cystic fibrosis.

We have observed seven pregnancies at risk for fetal cystic fibrosis where second-trimester amniotic fluid microvillar enzyme activities presented an unusual pattern. Low gamma-glutamyltranspeptidase and borderline alpha-glucosidase values were associated with normal aminopeptidase M and intestinal alkaline phosphatase values. All seven pregnancies went to term; five of the seven infants were affected with cystic fibrosis.