Unexpected Coexistence of a Derivative t(21;21) and Complementary Mosaic r(21) in a Female with Multiple Miscarriages. 
The case presented here describes a female patient with recurrent miscarriages and a normal microarray analysis result.  However, the coexistence of a robertsonian (21;21) translocation and complementary mosaic ring chromosome 21 was detected by karyotyping and FISH analysis.  Partial trisomy 21 was found with QF-PCR and microarray analysis in one of the fetuses.  The aim of this report was to emphasize the diagnostic importance of conventional cytogenetics.