title: Prenatal diagnosis of neural tube defects using the cholinesterases.
abstract: The usefulness of a cholinesterase assay and electrophoresis in the prenatal diagnosis of neural tube defects was investigated in amniotic fluids from 1,512 women. The assay used a alpha-naphthyl acetate as substrate and measured the combined activity of the enzymes acetylcholinesterase (AChE, E.C. 3.1.1.7) and cholinesterase (ChE, E.C. 3.1.1.8); the activity of both enzymes was raised in amniotic fluid from women carrying open NTDs. The alpha-naphthyl acetate assay distinguished fetuses with neural tube defects from normal fetuses more effectively than assays using acetylthiocholine as substate. A perfect score could be obtained on the sample tested when both enzyme assay and electrophoresis were done on those samples with activity greater than or equal to 4 mU. There was no correlation between gestational age between 13-21 weeks and activity of AChE + ChE (r = 0.03). The electrophoretic band of AChE activity proved to be a valuable diagnostic adjunct to both AFP or the AChE + ChE assay. A similar band or AChE activity was seen in adult brain and intestine but not in kidney, heart, liver, or lung, or in sera from women carrying normal or NTD fetuses.
mesh_terms: D000653:Amniotic Fluid / Q000201:enzymology; D002802:Cholinesterases / Q000378:metabolism*; D004796:Clinical Enzyme Tests; D003951:Diagnostic Errors; D005260:Female; D005865:Gestational Age; D006801:Humans; D009436:Neural Tube Defects / Q000175:diagnosis*; D011247:Pregnancy; D011296:Prenatal Diagnosis; D013379:Substrate Specificity
chemical_list: D002802:Cholinesterases