Genomic abnormalities in monoclonal gammopathy of undetermined significance.
Translocations involving immunoglobulin (Ig) loci and chromosome 13 monosomy (Delta 13) are frequent cytogenetic findings in multiple myeloma (MM). Similar chromosomal aberrations have been identified in the monoclonal gammopathy of undetermined significance (MGUS), but their prevalence and significance remain uncertain. Bone marrow from 72 patients with MGUS (n = 62) and smoldering MM (n = 10) was evaluated for translocations between the Ig heavy chain (IgH) and chromosomes 4, 11, and 16, translocations involving Ig light chain-lambda (IgL-lambda, and Delta 13. Fluorescence in situ hybridization (FISH) analysis was done on clonal plasma cells (PCs) detected by immunofluorescence (cIg-FISH) of the cytoplasmic light chain. We also studied cells for cyclin D1 and FGFR3 up-regulation by immunohistochemistry and immunofluorescence, respectively. Twenty-seven (46%) of 59 patients had IgH translocations, and 4 (11%) of 37 had an IgL-lambda translocation. A t(11;14)(q13;q32) was found in 15 (25%) of 59 patients, a t(4;14)(p16.3;q32) in 9% of patients, and a t(14;16)(q32;q23) in 5% of patients. All patients with t(4;14)(p16.3;q32) tested (n = 3) had intense cytoplasmic fluorescence with an anti-FGFR3 antibody. PC nuclear staining of cyclin D1 was only observed in patients with t(11;14)(q13;q32); Delta 13 was detected in the clonal PCs in 50% of patients. The percentage of abnormal PCs varied with any given abnormality. No obvious clinical or biologic correlations were associated with these chromosome abnormalities. Similar translocations are found in both MGUS and MM, including t(4;14)(p16.3;q32) and t(14;16)(q32;q23). Moreover, Delta 13 is common in MGUS and unlikely to play a predominant role in the evolution of MGUS to MM.
Fonseca
Rafael
R
Division of Hematology and Department of Internal Medicine, Mayo Clinic, Rochester, MN 55905, USA. fonesca.rafael@mayo.edu
Bailey
Richard J
RJ
Ahmann
Gregory J
GJ
Rajkumar
S Vincent
SV
Hoyer
James D
JD
Lust
John A
JA
Kyle
Robert A
RA
Gertz
Morie A
MA
Greipp
Philip R
PR
Dewald
Gordon W
GW
D000782:Aneuploidy; D002869:Chromosome Aberrations; D002880:Chromosomes, Human, Pair 11; D002882:Chromosomes, Human, Pair 13; D002883:Chromosomes, Human, Pair 14; D002885:Chromosomes, Human, Pair 16; D002894:Chromosomes, Human, Pair 4; D019938:Cyclin D1 / Q000032:analysis; D005455:Fluorescent Antibody Technique; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007147:Immunoglobulin Light Chains / Q000235:genetics; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D009101:Multiple Myeloma / Q000235:genetics; D010265:Paraproteinemias / Q000235:genetics*; D011379:Prognosis; D011505:Protein-Tyrosine Kinases; D051498:Receptor, Fibroblast Growth Factor, Type 3; D017468:Receptors, Fibroblast Growth Factor / Q000032:analysis; D014178:Translocation, Genetic
D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D017468:Receptors, Fibroblast Growth Factor; D019938:Cyclin D1; C496365:FGFR3 protein, human; D011505:Protein-Tyrosine Kinases; D051498:Receptor, Fibroblast Growth Factor, Type 3