Fetuses with microcephaly showed a significantly higher CPA/HA ratio (p < 0.001), higher CPL/OFD ratio (p < 0.001), and lower HC/AC ratio (p < 0.05); the difference in CFD/OFD ratio did not reach statistical significance (p > 0.05) (Figure 6). The gene discussed is CPA1; the disease is microcephaly.