Prenatal diagnosis and pregnancy outcomes of 22q11.2 duplication syndrome: analysis of 8 cases

Abstract

To investigate the relationship between 22q11.2 duplication and clinical phenotype. Eight fetuses with 22q11.2 duplication syndrome diagnosed by chromosome microarray analysis (CMA) through amniocentesis from February 2015 to March 2017 were enrolled in the study. The prenatal diagnostic indications, fetal ultrasound, chromosome karyotype, peripheral blood CMA results of parents, pregnancy outcomes and follow-up of postnatal growth and development were retrospectively analyzed. Prenatal serological screening indicated 6 cases with high risk of trisomy 21, 1 case with nuchal fold (NF) thickening and 1 case of maternal chromosomal balanced translocation. Fetal ultrasonography showed 1 case of NF thickening, 1 case of fetal cerebral ventriculomegaly and 6 cases with normal ultrasound. CMA demonstrated that the size of duplication was between 651 kb and 3.26 Mb, and 22q11.2 duplication. Parents' CMA results revealed that 6 cases inherited from one of the parents with normal phenotype, and the parents of 2 cases refused the CMA test. Two couples chose induced labor; 6 cases of continued pregnancy had normal phenotypes at birth. All 6 cases were followed up with longest of 3.5 years. The growth and psychological development were normal in 5 cases, and one case was growth retardation. There were no specific clinical phenotypes in 22q11.2 duplication syndrome, and most of them were inherited from one parent who has normal phenotype.