Female wang, 37 years old, 14 weeks of pregnancy, a total of 5 pregnancies, the first child was induced abortion, the second and third children were 60 days without fetal buds, the fourth child 60 days after the heart stopped beating. This pregnancy is the fifth. In order to ensure the smooth birth of the fetus, the doctor suggested amniocentesis for high-resolution CNV-seq test. The test found that the patient had about 95Mb heterozygous duplication on chromosome q12.11-q34, which is 13-trisomy syndrome. The 13-trisomy syndrome is also known as Patau's syndrome.80% of cases of this disease are free type 13-trisomy, karyotype is 46, XX (or XY), +13, and the rest are chimeric or translocated. The chimeric type generally has mild symptoms, and the translocation type is usually dominated by the 13th and 14th Roche translocations, and about 90% of 13q/13q Robertson translocations are equal brachymal chromosomes. If one of the parents is a 13q/13q translocation carrier, the abortion rate is 100% due to the occurrence of only three body or monomer zygotes. This also explains why the second, third and fourth fetuses of the pregnant woman are unable to develop normally, and she finally chooses to terminate the pregnancy to prevent the birth of the defective child.