Involvement of chromosome 13 in myelodysplastic syndromes.

We report 2 of 80 cases of myelodysplastic syndromes (MDS) cytogenetically studied, with involvement of chromosome 13. The first case had a t(6;13), and the second had a t(1;13). Abnormalities of chromosome 13 mainly involving loss of band 13q14 have been described in hematologic malignancies.

Involvement of chromosome 5 in large bowel cancer.

We present here 3 of 30 cases of large bowel cancer cytogenetically studied, with deletion of chromosome 5. One of them presented a terminal deletion and the other two an interstitial deletion of chromosome 5q. In all three cases the segment 5q12-22 was deleted.

Preferential involvement of 11q23-24 and 11p15 in breast cancer.

Thirty cases of breast cancer were cytogenetically studied by G-banding using direct tumor preparations. Among them 20 cases exhibited abnormalities of the long and/or short arm of chromosome 11. Thus, 11q was involved in 16 cases and 11p in ten cases.

Translocation (1;3)(p36;q21) in secondary leukemia.

A case of acute nonlymphocytic leukemia (M4) secondary to treatment for multiple myeloma is described. The patient presented a translocation t(1;3)(p36;q21) and monosomy 7.