Research Article Decrease in gamma-glutamyl transpeptidase activity in early amniotic fluid in fetal trisomy 18 syndrome. Br Med J (Clin Res Ed) 1982; 284 doi: https://doi.org/10.1136/bmj.284.6329.1593 (Published 29 May 1982) Cite this as: Br Med J (Clin Res Ed) 1982;284:1593 Article Related content Metrics Responses Peer review Related articles No related articles found.