[Application of chromosomal analysis for 29 cases of fetuses with nasal bone absence or hypoplasia]

Objectives: To explore the chromosomal analysis for fetuses with nasal bone absence or hypoplasia. Methods: This was a retrospective study on 29 pregnancies nasal bone absence or hypoplasia which underwent prenatal diagnosis, including chorionic villi (CV), amniotic fluid or cordocentesis.The indication of the procedures and results were evaluated. Result: Fifteen (51.7%, 15/29) of chromosome abnormities were diagnosed with indication of fetal nasal bone absence or hypoplasia, including eight with trisomy 21, two with trisomy 13, two with X chromosome aneuploidy and three with pathogenic copy number variations (CNVs) respectively.The incidence of chromosomal abnormalities in fetus with nasal bone hypoplasia (2/5, 40%) was lower than that in fetus with nasal bone absence (13/29, 54.2%). The incidence of chromosomal abnormalities in fetus with non-syndromic nasal bone absence or hypoplasia (4/13) was lower than that in fetus with syndromic nasal bone absence or hypoplasia (11/16). Conclusion: The incidence of chromosomal abnormalities in fetus with nasal bone absence or hypoplasia was higher and prenatal diagnosis was recommended for all types of the disease.For the fetus with nasal bone absence or hypoplasia, it is recommended to give priority to CNVs for prenatal diagnosis.