Abstract:

Objective: To analyze the prenatal ultrasonographic and genetic characteristics in fetuses with chromosome 22q11.2 microduplications. Methods: A total of 13 cases with 22q11.2 microduplications from Prenatal Diagnosis Center of Quanzhou Women′s and Children′s Hospital from January 1, 2018 to June 30, 2021 were included. Prenatal ultrasonographic characteristics, genetic causes and follow-up results were collected. Single nucleotide polymorphism array (SNP-array) and karyotype analysis were performed using amniotic fluid and umbilical cord blood. Results: The results of prenatal ultrasound demonstrated that case 1 had congenital diaphragmatic hernia and nuchal translucency (NT) thickening and choroid plexus cyst, and that case 2 and case 8 had the aberrant right subclavian artery. The results of SNP-array showed the microduplication fragments in 22q11.2 region range from 801.1 kb to 3.8 Mb in the enrolled 13 cases. Parental SNP-array verification indicated that two cases of microduplications were inherited from normal parents and that two of microduplications were de novo. At last, ten families chose to continue their pregnancies. Among them, 8 fetuses were followed up after birth without obvious abnormality, and 2 fetuses lost follow-up after birth. Conclusions: Interpretation of the clinical significance of prenatal 22q11.2 microduplications should be careful; the combination of prenatal ultrasonography and parental SNP-array verification will be helpful for the selection of pregnancy outcomes.

Key words: Polymorphism, single nucleotide, Chromosome karyotype analysis, Prenatal diagnosis, Chromosome deletion, Chromosome duplication, DNA copy number variations, 22q11.2 microduplications