Cytogenetic changes at 11q11, 11q23, and 17q11 in myelodysplastic syndrome.

Cytogenetic studies were performed on two patients with myelodysplastic syndromes. One patient was a 68 year old Japanese male in whose bone marrow cells two translocations were established, i.e., t(4;11)(q13;q23) and t(11;17)(q11?;q11), as well as other karyotypic changes (-6,-18,15p+). The other patient was a 74 year old white male whose bone marrow cells showed six marker chromosomes, i.e., der(5),t(5;17)(q12;q11), der(6),t(6;5)(q27;q22), der(8),t(8;11;?)(q11;q11----q23;?), der(11),t(11;?)(q11;?), an isochromosome of the long arm of chromosome #8, and a small G-group sized marker chromosome of unknown origin. Though the translocation patterns in the abnormal cells in these two cases were different, the breakpoints of the marker chromosomes were almost the same, i.e., 11q11, 11q23, and 17q11. Also, changes of chromosome #6 were observed; the first case showed monosomy 6 and the second a 6q+ marker chromosome. In these two cases of myelodysplastic syndromes, common sites of chromosome breakage and reunion of 11q23 and 17q11 were close to recently established sites of human cellular oncogene homologs, c-ets (11q23) and c-erbA (17q21----24). These associations draw attention to a possible relationship between chromosome changes in myelodysplastic syndromes and oncogene (or other gene) activation and/or dysfunction.