A Case of t(1;6)(p12;p11.1), Deletion 5q, and Ring 11 in a Patient with Myelodysplastic Syndrome with Excess Blasts Type 1.

We present the case of a 56-year-old male with myelodysplastic syndrome (MDS) whose bone marrow immunophenotype showed lower positivity for CD45 and positivity for CD34; 8.66% of this population also expressed partial positives for MPO, CD16, CD117, CD36, CD33, and CD71, as well as positives for CD13, HLA-DR, and CD11b. No alterations in the pattern of maturation were seen in CD13 vs CD16 and CD13 vs CD11b. An analysis of a population of mature lymphocytes revealed CD45 high CD3+ in 87.5% of cells, CD45 high CD19+ in 7.6% of cells, and 4.9% NK cells. These results are consistent with a myelodysplastic syndrome with an excess of blasts type 1. Chromosome analysis of the bone marrow revealed an abnormal karyotype with a t(1;6)(p12;p11.1) as well as deletion 5q and a ring 11 in 12 of the 20 metaphase cells examined. The t(1;6)(p12;p11.1) has not been reported in association with any particular hematological malignancy and provides further insight into the range of cytogenetic abnormalities in MDS.