Specificity and sensitivity of S100B levels in amniotic fluid for Down syndrome diagnosis.

Down syndrome (DS) is the most common chromosomal abnormality and is associated with an extra copy of the chromosome 21. Although several markers are commonly used during pregnancy for the screening of DS, the definitive diagnosis is based on karyotype after amniocentesis, which is an expensive and laborious analysis. S100B is an astrocyte protein which had its gene mapped to the long arm of chromosome 21.

S100B content and SOD activity in amniotic fluid of pregnancies with Down syndrome.

Objectives: We measured S100B levels and superoxide dismutase (SOD) activity retrospectively in amniotic fluid samples from pregnancies with normal and Down syndrome (DS) fetuses.

Design And Methods: Samples from 26 normal and 71 Down syndrome fetuses were studied. S100B protein levels were determined using LIA-mat Sangtec kit, and SOD activity was measured with the RANSOD kit.