Lower alkaline phosphatase activity and occurrence of an abnormal hybrid intestinal/tissue non-specific isoform in Down’s syndrome amniotic fluids

Abstract Quantitative and qualitative analysis of alkaline phosphatases (AP) was performed on amniotic fluid in 59 normal pregnancies and 14 Down’s syndrome (DS) pregnancies at 16, 18 and 19 weeks of gestation. In DS cases, intestinal and placental isoenzyme levels were significantly reduced ( P