OBJECTIVES: To use proteomics to identify and characterize proteins in maternal 
serum from patients at high-risk for fetal trisomy 21, trisomy 18, and trisomy 
13 on the basis of ultrasound and maternal serum triple tests.
METHODS: We performed a comprehensive proteomic analysis on 23 trisomy cases and 
85 normal cases during the early second trimester of pregnancy. Protein 
profiling along with conventional sodium dodecyl sulfate polyacrylamide gel 
electrophoresis/Tandem mass spectrometry analysis was carried out to 
characterize proteins associated with each trisomy condition and later validated 
using Western blot.
RESULTS: Protein profiling approach using surface enhanced laser 
desorption/ionization time-of-flight mass (SELDI-TOF/MS) spectrometry resulted 
in the identification of 37 unique hydrophobic proteomic features for three 
trisomy conditions. Using sodium dodecyl sulfate polyacrylamide gel 
electrophoresis followed by Matrix Assisted Laser Desorption Ionization - Time 
of Flight/Time of Flight (MALDI-TOF/TOF) and western blot, glyco proteins such 
as alpha-1-antitrypsin, apolipoprotein E, apolipoprotein H, and serum carrier 
protein transthyretin were identified as potential maternal serum markers for 
fetal trisomy condition. The identified proteins showed differential expression 
at the subunit level.
CONCLUSIONS: Maternal serum protein profiling using proteomics may allow 
non-invasive diagnostic testing for the most common trisomies and may complement 
ultrasound-based methods to more accurately determine pregnancies with fetal 
aneuploidies.