title: Amniotic fluid gamma-glutamyl transferase activity in trisomy 21 and neural tube defects.
abstract: The amniotic fluid gamma-glutamyl transferase (gamma GT) has been measured in normal pregnancies (n = 128), six pregnancies associated with trisomy 21 and 12 pregnancies involving a foetus with a neural tube defect. In normal pregnancies, the amniotic fluid gamma GT activity falls during the second trimester, the level at 20 wk being 60% of that at 14 wk. In the six cases of trisomy 21 and 8 of the 12 cases with neural tube defects, the gamma GT levels were below the 95% confidence limit.
mesh_terms: D000653:Amniotic Fluid / Q000201:enzymology*; D004314:Down Syndrome / Q000201:enzymology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D009436:Neural Tube Defects / Q000201:enzymology*; D011247:Pregnancy; D005723:gamma-Glutamyltransferase / Q000032:analysis*
chemical_list: D005723:gamma-Glutamyltransferase