Detection of the Cytogenetic Aberrations in Multiple Myeloma by Using Microrray Comparative Genomic Hybridization

Abstract

To detect the molecular cytogenetic abnormalities of multiple myeloma (MM) by using microrray-based comparative genomic hybridization (array-CGH) technology and to investigate its value of application in MM. The whole-genoine copy number variants (CNV) of bone marrow samples acquired from 20 cases of newly diagnosed MM patients were detected by genome-wide hybridization and scanning by CytoScan 750K Array (Affymetrix). At the same time, the chromosome abnormalities of bone marrow cells were detected by karyotype analysis and FISH using 9 specific probes: D13S319, RB1, p53, 1q21, IgH, IgH/CCND1, IgH/FGFR3, IgH/MAF, IgH/MAFB. Among the 20 MM patients, the incidence of chromosome abnormalities detected by karyotype analysis, FISH and array-CGH were 15%, 65% and 90%, respectively. The types of CNV detected by array-CGH included the gain (106), loss (156) or UPD (23). There were many different CNVs in every chromosomes except chromosome 5, 9, 18, 21 and Y. Comparison of chromosome abnormalities detected by FISH and array-CGH showed that, the positive ratio of del (13q) was 35% and 40% respectively; the positive ratio of amp (1q) was 40% and 50% respectively; the positive ratio of del (17p) was both 15%. FISH detection showed 8 cases with IgH rearrangement, meansahile the array-CGH detection showed that 4 cases had amp (11q13) (CCND1 gene), 3 cases had amp (16q23) (MAF gene), 1 case had amp (4p16) (FGFR3 gene) and 2 cases had amp (20q12) (MAFB gene). Besides, many other new chromosome abnormalities were found. More than half of MM patients have cytogenetic changes, and most of them are complex chromosomal abnormalities. By using array-CGH, more chromosome abnormalities can be detected and more cytogenetic information can be provided for clinician.