The levels of AFP-L3 in gravidas carrying trisomy 21 and trisomy 18 fetuses were 1.73 (0.05–6.84) and 1.66 (0.60–5.96) MoMs, respectively, which were also higher than the 0.85 (0.24–2.48) MoM20 in the control subjects (all P < 0.001). The gene discussed is AFP; the disease is trisomy.