title: Decrease in gamma-glutamyltransferase activity in early amniotic fluid in fetal trisomy 18 syndrome.
mesh_terms: D000653:Amniotic Fluid / Q000201:enzymology*; D002869:Chromosome Aberrations / Q000175:diagnosis*; D025063:Chromosome Disorders; D005260:Female; D006801:Humans; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D014314:Trisomy; D005723:gamma-Glutamyltransferase / Q000378:metabolism*
chemical_list: D005723:gamma-Glutamyltransferase