Multicolour spectral karyotyping identifies new translocations and a recurring pathway for chromosome loss in multiple myeloma

• Published in: British journal of haematology Vol. 112; no. 1; pp. 167 - 174
• Main Authors: Sawyer, Jeffrey R., Lukacs, Janet L., Thomas, Edward L., Swanson, Charles M., Goosen, Linda S., Sammartino, Gael, Gilliland, John C., Munshi, Nikhil C., Tricot, Guido, Shaughnessy, John D., Barlogie, Bart
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.01.2001; Blackwell; Blackwell Publishing Ltd
• Subjects: Biological and medical sciences; Chromosome Deletion; chromosome instability; Chromosomes, Human, Pair 1; Chromosomes, Human, Pair 11; Chromosomes, Human, Pair 13; Chromosomes, Human, Pair 14; Chromosomes, Human, Pair 16; Chromosomes, Human, Pair 22; Chromosomes, Human, Pair 8; cytogenetics; Hematology; Humans; Immunodeficiencies. Immunoglobulinopathies; Immunoglobulinopathies; Immunopathology; Karyotyping - methods; Medical sciences; multiple myeloma; Multiple Myeloma - genetics; novel translocations; spectral karyotyping; Translocation, Genetic; Chromosomal aberration; Human; Cytogenetics; Abnormal chromosome; Genetics; Myeloma; Spectral analysis; Karyotype; Chromosome translocation
• ISSN: 0007-1048; 1365-2141
• DOI: 10.1046/j.1365-2141.2001.02546.x

Multicolour spectral karyotyping (SKY) was performed on primary tumour specimens from 100 patients with multiple myeloma (MM) that showed complex clonal chromosome aberrations not fully characterized by G‐banding. In this study, SKY was able to identify or revise translocations with breakpoints involving 14q32, 11q13 or 8q24 in 32 patients (32%). Five new recurring translocations were identified, two of which involved chromosome 22. A subtle reciprocal translocation t(14;22) (q32;q11∼12) was identified using SKY in two patients and a second, much larger, translocation t(11;22)(q13;q13) was identified using G‐banding in three patients. A third new translocation was identified in two patients using SKY and G‐banding as der(7)t(7;7)(p15∼22;q22∼32). Twenty‐three patients (23%) showed the loss of 8p by whole‐arm translocations with different whole‐arm donor chromosomes. Among this group, two new recurring whole‐arm translocations involving the centromeric breakpoint 8q10 were identified as der(8;20)(q10;q10) and der(8;18) (q10;q10) in three patients each. In addition, a novel pattern of three‐way translocations involving the clonal evolution of the t(8;22)(q24;q11) by the subsequent loss of 8p by whole‐arm translocations was found in three patients. The chromosome instability identified here demonstrates that the loss of 8p can occur by multiple whole‐arm translocations, indicating a new pathway for the loss of a specific chromosome region in MM.