{Reference Type}: Case Reports
{Title}: Discrepancy between non-invasive prenatal testing result and fetal karyotype caused by rare confined placental mosaicism: A case report.
{Author}: Li Z;Lai GR;
{Journal}: World J Clin Cases
{Volume}: 10
{Issue}: 24
{Year}: Aug 2022 26
{Factor}: 1.534
{DOI}: 10.12998/wjcc.v10.i24.8641
{Abstract}: <B>BACKGROUND: </B>Confined placental mosaicism (CPM) is one of the major reasons for discrepancies between the results of non-invasive prenatal testing (NIPT) and fetal karyotype analysis.<BR><B>METHODS: </B>We encountered a primiparous singleton pregnant woman with a rare CPM consisting of 47,XY,+21; 47,XXY; and 46,XY, who obtained a false-positive result on NIPT with a high risk for trisomy 21. Copy-number variation sequencing on amniotic fluid cells, fetal tissue, and placental biopsies showed that the fetal karyotype was 47,XXY, while the placenta was a rare mosaic of 47,XY,+21; 47,XXY; and 46,XY.<BR><B>CONCLUSIONS: </B>The patient had a rare CPM consisting of 47,XY,+21; 47,XXY; and 46,XY, which caused a discrepancy between the result of NIPT and the actual fetal karyotype. It is important to remember that NIPT is a screening test, not a diagnostic test. Any positive result should be confirmed with invasive testing, and routine ultrasound examination is still necessary after a negative result.