[Cytogenetic abnormalities of 50 MDS patients by FISH detection and conventional karyotype analysis]

This study was purposed to compare detectable rate of cytogenetic abnormalities including -5/5q-, -7/7q-, 20q-,+8, and -Y in MDS by FISH and metaphase cytogenetics, and to investigate the relationship between cytogenetic abnormalities and progression from MDS to acute leukemia. Metaphase cytogenetics and FISH testing for -5/5q-, -7/7q-, 20q-,+8, and -Y were performed in 50 bone marrow samples obtained from patients with MDS diagnosed according to the WHO criteria (2008). Evolution from MDS to AML was followed up for each patient. The results showed that the cytogenetic abnormalities including -5/5q-, -7/7q-, 20q-,+8, and -Y were identified in 25 (50%) of 50 by metaphase cytogenetics, and in 20 (40%) of 50 by FISH. -5/5q-, 7/7q-, 20q- , +8, or -Y was identified by metaphase cytogenetics in 3 (6%) of 50, 13 (26%) of 50, 6 (12%) of 50, 12 (24%) of 50, and 1 (2%) of 50, respectively, and by FISH in 3 (6%) of 50, 10 (20%) 0f 50, 3 (6%) of 50, 10 (20%) of 50, and 1 of 50 (2%), respectively. The detectable rate ranking was -7/7q- >+8>20q->-5/5q->-Y. 47 patients received allogeneic hematopoietic stem cell transplantation. In the IPSS poor prognosis group, 6 (46.2%)of 13 received transplantation before progression to acute leukemia. In the IPSS good prognosis group, 10 (45.5% ) of 22 received transplantation before progression to acute leukemia. In the IPSS intermediate prognosis group, 2 (16.7%) of 12 received trans- plantation before progression to acute leukemia. The rate of progression to acute leukemia was 7.7% (1/13) in the IPSS poor prognosis group, 4.5% (1/22) in the IPSS good prognosis group, and 58.3% (7/12) in the IPSS intermediate prognosis group. The low rate of progression to acute leukemia in the IPSS poor prognosis group might be associated with the high rate of allogeneic hematopoietic stem transplantation. It is concluded that there is higher detectable rate for detecting a certain chromosome by FISH probe than that by metaphase cytogenetics, especially for detecting low clone chromosomal abnormalities and mitotic figures less than 20. There is no difference between IPSS good prognosis group and IPSS poor prognosis group in our study probably because of allogeneic hematopoietic stem cell transplantation.