Using Clinprot System To Filter Out Protein Markers Of Trisomy 21 Syndrome

ObjectiveClinProtTM system was used to compare the mass spectrum of amniotic fluid between Trisomy 21 syndrome and normal control group(gestational age is from 17 to 22 week),to explore the potential diagnostic protein for Trisomy 21 syndrome in amniotic fluid.MethodsWe divided the amniotic fluid of 30 Trisomy 21 syndrome fetuses(from 17 to 22 gestational age.collecting 2,3,6,13,4 and 2 samples) and 180 normal fetuses(from 17 to 22 gestational age, collecting 30 samples)into Trisomy 21 syndrome group and normal group. Every group were respectively divided into six gestational age groups(17-22W). Depending on the different gestational age, 12 groups of amniotic fluid samples were mixed in equal valum. After the amniotic fluid samples were concentrated in 10 times, respectively, functional magnetic bead was used to purify amniotic fluid samples, capture proteins and peptides in amniotic fluid of Trisomy 21 syndrome fetus and healthy controls.Then MALDI-TOF-MS and bioinformative software were used for protein profiling. GA was used to evaluate the sensitivity and specificity of the different proteins, and then to establish the discriminable model.Results1 The protein profilings of 3 repeated experiments of 12 groups were similar. 2.Taking 22 gestational age for example,We randomly selected 6 protein peaks with mass charge ratio (m/z) 867,1450,3000,4210,6175 and 7174 Da in high,middle and low molecular weight regions and found that the average coefficient of variation was 0.501 which is small enough to show good reproducibility of ClinProtTM.3. Totally 44 difference protein peaks were found when analysing by ClinproTool software(P<0.05).we found that protein peaks with m/z 3673Da and 862Da were the most differently expressed The ability of this two protein to distinguish Trisomy 21 syndrome and normal group were good.Using GA.the system gained a diagnostic model with 5 proteins.The mass charge ratio of these proteins were 3762.68Da,7988.89Da,3911.26Da, 3709.99Da and1450.5Da. The recognition rate of this model to disease and control group was all 100%.Conclusions1. ClinProtTM system which have a well stability and sensibility can be used to study the protein expression profile of the amniotic fluid of Trisomy 21 syndrome.2. Screend m/z 3673Da and 862Da protein may be the potential diagnostic marker for Trisomy 21 syndrome.