The gene variant involved included the single gene MPCH 2 and MPCH 11, which is associated with human microcephaly, and HDAC8, TUBGCP6, NIPBL, FANCI, PDHA1, UBE3A, CASK, TUBB2A, PEX1, PPFIBP1, KNL1, SLC26A4, SKIV2L, COL1A2, EBP, ANKRD11, MYO18B, OSGEP, ZEB2, TRIO, CLCN5, CASK, and LAGE3. The live birth rate of fetal microcephaly in the syndromic microcephaly group was significantly higher than that in the primary microcephaly group [62.9% (117/186) vs 31.56% (12/38), p = 0.000]. The gene discussed is KNL1; the disease is Primary microcephaly.