Complex karyotypic mosaicism as a result of non-disjunction and subsequent centromere fission.

Karyotypic discrepancy among four different cell types is described in tissues derived from a pregnancy terminated because of chromosomal anomalies. Chorionic villus cells demonstrated 46,XX (direct preparation) and 46,XX/47,XX,+mar1 (cultured cells) karyotypes, while fetal skin fibroblasts had a karyotype of 47,XX,+18 and the placenta showed a triple mosaicism of 47,XX,+18/47,XX,+mar1/48,XX,+18,+mar2. The origin of this complex chromosomal distribution and its significance are discussed in comparison with findings in similar cases.