二例伴有i(20q-)重复的骨髓增生异常综合征的临床和实验研究

Clinical and experimental study of two cases of myelodysplastic syndromes with double isochromosome 20q-anomaly

目的探讨伴有i(20q-)重复的骨髓增生异常综合征(MDS)临床和实验室特征。方法骨髓细胞经直接法和24h培养后按常规方法制备染色体,用RHG显带技术进行核型分析,并以20q端粒探针和20q12单一序列探针进行荧光原位杂交(FISH)检测。结果2例的临床和血液学改变符合MDS诊断;染色体核型分析揭示2例患者均有i(20q-)重复例1为46,XX,der(20)?i(20q-)[6]/46,idem,der(6)i(6p)[1]/47,idem,+der(20)?i(20q-)[3]/47,idem,der(6)i(6p),+der(20)?i(20q-)[20],例2为45,XY,-7,der(20)?i(20q-)[17]/46,idem,+der(20)?i(20q-)[3]。其中1例患者经双色FISH检测证实两个衍生的20号染色体为伴有中间缺失的20号长臂等臂染色体。结论i(20q-)重复是MDS的一种少见的再现性的核型异常,预后不佳。

Objective To explore the clinical and laboratory characteristics of two myelodysplastic syndromes (MDS) patients with double isochromosome 20q-anomaly. Methods Bone marrow cell chromosome preparations were made with both direct method and short-term culture. Karyotype analysis was performed by R-banding technique, and dual-color FISH (fluorescence in situ hybridization) by using a 20q telomeric probe and a sequence-specific probe for 20q12. Results The clinical and hematological findings were comparable with diagnosis of MDS. Karyotype analysis showed that both patients had double isochromosome 20q-anomaly: case 1 is 46, XX, der(20)?i (20q-)[6]/ 46, idem, der (6)i (6p)[1]/ 47, idem, +der (20)?i (20q-)[3]/ 47, idem, der (6)i (6p), +der (20)?i (20q-)[20]; case 2 is 45, XY,-7, der (20)?i (20q-)[17]/46, idem, +der (20)?i(20q-)[3]. Two derivative chromosomes 20 were proved 20q isochromosomes with interstitial deletions by dual-color FISH in one patient. / 46, idem, der (6)i (6p)[1]/ 47, idem, +der (20)?i (20q-)[3]/ 47, idem, der (6)i (6p), +der (20)?i (20q-)[20]; case 2 is 45, XY,-7, der (20)?i (20q-)[17]/46, idem, +der (20)?i(20q-)[3]. Two derivative chromosomes 20 were proved 20q isochromosomes with interstitial deletions by dual-color FISH in one patient. / 47, idem, der (6)i (6p), +der (20)?i (20q-)[20]; case 2 is 45, XY,-7, der (20)?i (20q-)[17]/46, idem, +der (20)?i(20q-)[3]. Two derivative chromosomes 20 were proved 20q isochromosomes with interstitial deletions by dual-color FISH in one patient. Conclusions Double isochromosome 20q-anomaly is a rare recurrent karyotype abnormality in MDS, and signals a poor prognosis.