Test Description:
AChE is a diagnostic test employed along with amniotic fluid AFP to detect open fetal defects. AChE leaks into the amniotic fluid from an opening in the neural tube or ventral wall of pregnancies affected by open fetal defects, leading to detectable levels of AChE in the amniotic fluid. AChE testing is indicated when the amniotic fluid AFP level exceeds 2.0 MoMs or when there is an increased risk for an open fetal defect due to elevated MSAFP, an abnormal ultrasound or a family history of an open fetal defect, regardless of the amniotic fluid AFP level. An estimated 98% of open neural tube defects are detected with AFAFP and AChE testing. The detection rate for anencephaly is even higher. Gastroschisis is also associated with a very elevated amniotic fluid AFP, and the AChE is positive in over 95% of cases. Alternatively, omphalocele may result in normal or mildly elevated amniotic fluid AFP levels, while AChE is normal in over 95% of cases.
Methods:
Polyacrylamide gel separation by electrophoresis of acetylcholinesterase (AChE) in amniotic fluid.
Specimen Requirements:
AChE results can be reliably interpreted between 15 weeks and 24 weeks 6 days gestation. AChE testing is performed on amniotic fluid aliquots received through the MSU Cytogenetics Laboratory. For specimen requirements, call 517-353-2032 or 1-877-TEST-DNA.
Shipping Instructions:
Ship immediately or via overnight delivery to the MSU Cytogenetics Laboratory, B123 Life Sciences Bldg, East Lansing, MI 48824. To arrange shipment call (517) 353-2032 or (877) TEST-DNA.
Turnaround Time: AChE testing is completed once weekly. Amniotic fluid AFP results are reported in conjunction with AChE, when requested.
Test CPT Code: 82013