Diagnostic follow-up for a case of mosaic trisomy 22 by non-invasive prenatal testing / 中华检验医学杂志

ABSTRACT

Objective To estimate prenatal diagnoses strategy with abnormal results of non-invasive prenatal testing (NIPT) based on a case of mosaic for trisomy 22.Methods The pregnanct woman was recruited from Department of Prenatal Diagnosis Center of Xinhua Hospital.Ultrasound scans suggested fetal nuchal translucency was 3.5 mm.Peripheral venous blood was drawn from the pregnant woman for NIPT at 12+2 weeks gestation.For further prenatal diagnosis, amniocentesis was conducted at 16+2 weeks gestation, and karyotype analysis combination with chromosome microarray analysis (CMA) was executed to analysis amniocytes.Results NIPT results suggested that chromosome 21, 18 and 13 were normal and supplementary reports suggested that chromosome 22 were slightly above the normal range.Karyotype analyzed 35 cultured cells.Each of them revealed a normal female karyotype.However, CMA results suggested that chromosome 22 gain mosaic and its copy number was 2.26.The fetus was diagnosed as high possibility of mosaic for trisomy 22.Conclusions Combined with the NIPT results, which was slightly gain mosaic of chromosome 22, a prenatal diagnosis strategy were proposed.When NIPT results suggest chromosomal abnormities, karyotype analysis combination with CMA to diagnose were recommended.