Amniotic fluid microvillar enzyme activity in fetal malformations

Area of Science:

• Prenatal diagnostics
• Biochemistry
• Medical genetics

Background:

• Amniotic fluid microvillar enzyme activity assays are increasingly used for prenatal diagnosis of cystic fibrosis.
• Establishing normal enzyme values is crucial for interpreting diagnostic results.
• Congenital malformations and genetic disorders can affect enzyme activity.

Purpose of the Study:

• To determine normal median values for amniotic fluid microvillar enzymes during specific gestational weeks (15-20 weeks).
• To investigate the relationship between enzyme activities and various pregnancy complications, including congenital malformations, monogenic inherited diseases, and chromosomal aberrations.
• To explore the diagnostic potential of these enzyme assays beyond cystic fibrosis.

Main Methods:

• Collected amniotic fluid samples from 177 normal pregnancies (15-20 weeks gestation).
• Determined median enzyme activity values in normal pregnancies.
• Compared enzyme activities in pregnancies with congenital malformations, monogenic diseases, and chromosomal aberrations.

Main Results:

• Established normal median values for amniotic fluid microvillar enzymes.
• Found increased trehalase activity is indicative of fetal kidney diseases and radial-renal syndrome (associated with elevated Gamma-glutamyl transferase (GGT) activity).
• Observed that low enzyme activities may suggest chromosomal aberrations in the absence of intestinal obstruction.

Conclusions:

• Amniotic fluid enzyme analysis, particularly trehalase and GGT, holds diagnostic significance for fetal kidney conditions and chromosomal abnormalities.
• Enzyme activity patterns can differentiate between various fetal conditions, aiding in prenatal diagnosis.
• Further research with expanded data may enable the development of diagnostic procedures for a wider range of non-cystic fibrosis related prenatal conditions.