Based on our findings, in Down’s syndrome pregnancies, the mean MoM value decreased to 0.64, 0.72 and 0.55 for PAPP-A, and increased to 3.92, 6.11 and 1.98 for free β-hCG in ≤35, 35–39 and ≥40 age-groups, respectively. The gene discussed is PAPPA; the disease is Down syndrome.