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Determination of cholinesterase and acetylcholinesterase in amniotic fluid
Author(s) -
Elejalde B. Rafael,
Peck Gregory,
Elejalde Maria Mercedes de
Publication year - 1986
Publication title -
clinical genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 102
eISSN - 1399-0004
pISSN - 0009-9163
DOI - 10.1111/j.1399-0004.1986.tb00812.x
Subject(s) - amniotic fluid , acetylcholinesterase , prenatal diagnosis , fetus , anencephaly , medicine , gastroschisis , trisomy , obstetrics , endocrinology , chemistry , pregnancy , biology , enzyme , biochemistry , genetics
The determination of acetylcholinesterase (AChE) has been shown to be as specific as alphafeto‐protein (AFP) for the prenatal detection of open neural tube defects although AFP remains the method of choice. This paper describes a semi‐automated technique for the analysis of acetylcholinesterase in amniotic fluid that: A) reduces the cost of the procedure; B) allows for a larger number of samples to be run at a time; and C) provides for more accurate and reproducible procedures and results. Six fetuses with neural tube defects (2 with gastroschisis and 3 where one twin was dead) were detected and found to have elevated AChE, TChE and 2 bands by electrophoresis. Quality control procedures using both pure enzyme and amniotic fluid with low and high levels of the enzyme are described. The analysis of 340 amniotic fluids of normal pregnancies indicates that the normal value for AChE is 5.17 ± 2.63 mU/ml (97% confidence interval for the mean 4.84‐5.49 mU/ml. A group of 27 abnormal pregnancies provides evidence that fetal vomiting and regurgitation, fetal demise, multiple cysts syndrome, idiopathic IUGR, arthrogryposis multiplex, hydrocephaly (stenosis of aqueductus), trisomy 21, trisomy 18, hydronephrosis, pyloric stenosis, heart malformation, ectopia cordis and multiple gestation produce elevated levels of pseudocholinesterase (PChE) in amniotic fluid. The use of pseudocholinesterase levels in amniotic fluid for prenatal diagnosis is proposed and discussed in view of its elevated levels in abnormal pregnancies where AChE is normal. The normal values for PChE are 23.86 mU/ml (mean) and 5.83 for standard deviation. Electrophoretic analysis was performed on all samples with values higher than one standard deviation above the mean. The AChE band was found only in fetuses with open neural tube defects and pyloric stenosis.