Unique cytogenetic features of primary myelodysplastic syndromes in Chinese patients.

Myelodysplastic syndromes (MDS) are a heterogeneous group of myeloid neoplasms. Chromosomal abnormalities have been detected in 40-70% patients with primary MDS and are heterogeneous among patients of different races and from different backgrounds. In the current study, 351 Chinese adult patients with primary MDS were retrospectively analyzed for their chromosomal abnormalities by karyotyping. Among the 237 cases (67.5%) of chromosomal abnormalities, 99 were copy number changes alone (41.7%), 70 were structural abnormalities alone (29.5%), and 68 displayed both of these changes (28.8%). Overall, the frequency of -5/5q-/del(5)(q13-33) was 5.1% in these Chinese MDS patients, which was lower than that in the MDS patients of western countries (8.7-23.4%), and the incidence of 5q- syndrome was only 0.3% in Chinese MDS patients. On the other hand, the frequencies of trisomy 8 (19.1%) and -20/20q-/del(20)(q11-13) (9.4%) were higher than those in western countries (1.2-7.0% and 2.0-3.5%, respectively). Chromosomal translocations were also detected in 31 cases (13.1%) including 12 rare translocations that have not been reported in MDS patients before. In addition, i(17)(q10) was detected in nine cases (3.8%), of which six cases only had this single abnormality. According to the IPSS chromosomal prognostic classification, the incidence of poor-risk karyotypes increased in the advanced WHO subtypes (p < 0.001). Together, we detected the unique cytogenetic features of chromosomal abnormalities and some rare translocations of MDS among Chinese patients.