The maternal serum screening of case 1 were not available while the results of case 2 revealed a Down syndrome risk of 1/576 calculated from the levels of 1.67,3.11,0.83,0.98 and 0.63 multiples of the median (MoM) for a-fetoprotein (AFP), β-human chorionic gonadotropin(β-hCG), unconjugated estriol (uE3), pregnancy-associated plasma protein-A (PAPP-A) and nuchal translucency (NT), respectively. This evidence concerns the gene AFP and Down syndrome.