Partial trisomy 13 due to maternal translocation t(7;13)(p22q14).

The third child of a mother with a balanced translocation (7;13) revealed a partial trisomy of chromosome 13. The cytogenetic study by conventional techniques and GTG, QFQ, THA and CBG banding techniques showed the chromosomal complement of the proposita to be 46,XX,-7,+t(7;13)(7qter leads to 7p22::13q14 leads to 13qter). A prominent intensely fluorescent satellite was observed on the 13q- of the patient's grand-mother. This satellite was not found on any chromosome in any other member of the family.