Cytogenetics of multiple myeloma

Great studies of multiple myeloma (MM) strongly suggested that specific chromosomal changes are of prognostic significance in patients with MM1. We have performed cytogenetic analysis and recently fluorescent in situ hybridization (FISH) on 43 cases of MM. Clonal chromosomal changes were present in 24 (56%) cases. Hyperdiploid karyotype was found in 12 (50%) cases, hypodiploid in 8 (33%) cases, and 4 (17%) cases had a pseudodiploid karyotype. The most common numerical abnormalities were gains of whole chromosomes 15, 11, 3 and 6. Whole chromosome losses were also frequent involving chromosomes X, 13, 14, and 8. Most cases showed also structural rearrangements 71% (n = 17): del(1p), dup(1q), del(5q), del(13q), del(17p) and t(11;14)(q13;q32) (n = 4, 17%). Chromosome -13/13q deletion was found in 42% (n = 10) cases; complete loss of 13 was observed in 67% (n = 7) cases, whereas 33% (n = 3) had interstitial deletions. In the majority of the cases there was a mixture of abnormal and normal metaphases.