Fluorescence in situ hybridization showed in the marker chromosome positive dicentric signals for the chromosome 15 centromere-specific alpha satellite DNA probe (D15Z1) and negative signals for the SNRPN probe (15q11-13), thus establishing a cytogenetic diagnosis of 47,XX,+mar.ish idic(15)(q11-q13)(D15Z1++,SNRPN-) for both fetuses.The parental karyotypes were normal.