Balanced translocation in fetal wastage

A balanced reciprocal translocation involving the long arms of a No. 4 and a No. 11 chromosome, t(4;11) (q25;q13). was found in a mother who had had one spontaneous first trimester abortion and 2 abnormal infants, as well as in her 2 phenotypically normal children. This translocation was not detectable by conventional karotyping since the two exchanged chromosome segments are almost identical in size, it was demonstrated by the new banding technic which allow us to recognize and to identify each chromosome and its segments accurately.