The analyses stress the importance of using a software which has the possibility to separate the level of a biochemical risk by correlating PAPP-A and free beta HCG and, by adding the NT marker, calculate the level of a final risk of Down syndrome.
Our model shows a very low number of reprogramming rearrangements as assessed by a high-resolution whole genome CGH-array hybridization, and it reproduces several cellular pathologies seen in primary human DS cells, as assessed by automated high-content microscopic analysis.
We present the case of a pregnant woman with low free beta-HCG in maternal serum Down syndrome screening that led to prenatal diagnosis of a fetus with 46,XY,der(4)t(4;11)(p14; q25).
We concluded that in trisomy 21 the high tissue HCG concentration and expression of LH/HCG receptor in the trophoblast may reflect the relative immaturity of the trophoblastic tissue whereas in trisomy 18, the very low concentration of endogenous HCG, associated with an over-expression of LH/HCG receptor in the trophoblast, is probably secondary to the poor differentiation of the cytotrophoblast.
The increase in hCG promoter activity in DS-derived fibroblasts suggests a possible role for a transcriptional factor located on the human chromosome 21 by either directly or indirectly interacting with the beta5-promoter.
Significant correlations were found for AFP and UE3 in the controls and for intHCG and F beta HCG in both the control and the Down's syndrome pregnancies.
The addition of two new markers in maternal serum, estriol and HCG, to those already known, namely the level of maternal serum alfa-fetoprotein and maternal age, considerably improves the expected results of a screening strategy for Down syndrome.