Prenatal diagnosis of complex rearrangement of chromosome 21: The significance of interphase and metaphase fluorescence in situ hybridization and comparative genomic hybridization


Key Clinical Message

Maternal serum screening–positive patient had prenatal diagnosis with amniotic fluid, which showed inconsistent results between interphase fluorescence in situ hybridization (three signals of 21q22.13-21q22.2) and G-banding analysis (46,XY). Further analyses proved that the fetus had extremely complex rearrangements of chromosome 21, including the interstitial duplication of Down syndrome critical region.