Clinical implications of abnormalities of chromosomes 1 and 13 in multiple myeloma

Multiple myeloma with a variant Burkitt-type translocation, t(2;8)(p12;q24), associated with hyperammonemia

We report an 82-year-old Japanese woman with multiple myeloma (MM). She developed disorientation due to hyperammonemia after melphalan and prednisolone therapy and abruptly died with a rapid clinical course. Karyotypic analysis of bone marrow showed complex abnormalities including a variant Burkitt-type translocation, t(2;8)(p12;q24), but the patient had IgG-lambda type M-proteinemia. Although patients with MM associated with hyperammonemia have been sporadically reported and their prognosis is poor, specific chromosomal abnormalities in the lesion have not been well characterized. It is, therefore, important to accumulate such patients to find a possible relationship between hyperammonemia and chromosomal abnormalities.

Sequential analysis of chromosome aberrations in multiple myeloma during disease progression

PURPOSE

Several chromosomal aberrations have been associated with molecular pathogenesis and classification of multiple myeloma. It is not known whether the expression of abnormal karyotypes is consistent in patients during disease progression. Herein, we report on sequential analysis of conventional cytogenetics as well as fluorescence in situ hybridization (FISH) data of 79 bone marrow specimens from 38 patients with myeloma who were longitudinally followed.

PATIENTS AND METHODS

We determined and characterized the development of additional chromosomal aberrations during progressive disease.

RESULTS

Overall, conventional cytogenetics detected an abnormal karyotype in 42% of the samples, whereas this increased to 69% by FISH. Among the cases with an abnormal conventional karyotype, 52% had a hyperdiploid subtype of myeloma. Progressive disease was correlated with an increased complexity of genetic abnormalities, which in the majority, consisted of structural aberrations acquired in later stages of disease. Using conventional cytogenetics, rearrangements of chromosome 1 were the most common structural abnormality (15%). In the majority, these rearrangements consisted of unbalanced translocations of 1p and 1q; however, no specific locus was predominantly affected. Second in frequency were structural aberrations of chromosomes 8 and 17 (6%). The frequency of del(13q) by FISH was 40% and did not increase in later stages of the disease, suggesting that del(13q) is not a genetic event associated with disease progression. Change of ploidy category during disease progression occurred in a minority of the cases.

CONCLUSION

This study supports the notion that cytogenetic abnormalities in multiple myeloma are not random. Particular chromosomal alterations are associated with disease progression, whereas others show a stable pattern during the course of the disease.

Comparative genomic hybridisation identifies two variants of smoldering multiple myeloma

Two variants of smoldering multiple myeloma (SMM) have been recognised: (i) an evolving type, characterised by a progressive increase in the M-protein size and short time to progression to overt multiple myeloma (MM) and (ii) a non-evolving type, with a long-lasting, stable M-protein and longer time to progression. Comparative genomic hybridisation (CGH) analyses in both subtypes of SMM (seven evolving and eight non-evolving SMM) were performed. Evolving SMM showed cytogenetic changes consistent with those found in de novo symptomatic MM (1q gains, chromosome 13 deletions) while the non-evolving variant showed no 1q gains and deletions were uncommon.

Allelic imbalance of chromosome 1q in esophageal squamous cell carcinomas from China: a novel region of allelic loss and significant association with differentiation

Our previous work has shown that a number of genes locating on 1q21 were down-regulated in esophageal squamous cell carcinomas (ESCC) and they may involve in carcinogenesis. To determine whether chromosome 1q LOH occurs in ESCC, we analyzed LOH in 61 ESCCs using 18 microsatellite markers on chromosome 1q. Forty-six of 61 (75.4%) tumors presented LOH at one or more loci. A significant association was found between chromosome 1q LOH and histopathological grade. LOH on D1S3466 had a negative correlation with family history, whereas LOH on D1S2777 positively correlated with smoking. These results suggest this region harbor putative tumor suppressor gene(s) contributing to tumorigenesis and differentiation in ESCC.