Detection of 13th chromosome deletion frequency by fluorescent in situ hybridization method in patients with multiple myeloma

Abstract

INTRODUCTION: Multiple myeloma (MM) is a malignant hematological disease characterized by malignant proliferation of a single plasma cell clone leading to monoclonal protein in plasma or urine. Presence of monoallelic loss of chromosome 13 (del13) or loss of long arm (del13q) indicates poor prognostic outcome in patients treated with standard chemotherapy. Del13/del13q is detected by FISH method in approximately half of newly diagnosed MM patients. METHODS: 42 patients diagnosed with MM according to the criteria of the International myeloma working group and treated at research and education hospital, were included in this study. Clinical, laboratory, pathological data were analyzed retrospectively and genetic data obtained by FISH method. RESULTS: 26 patients were female (61.9%) and 16 were male (38.1%). The mean age was 62. Del13 results were obtained in 30 of 42 patients, while positive in 6 patients (20%) negative in 24 patients (80%). Among the 30 patients with chromosome 13 results, 4 had IgA, 19 had IgG type monoclonal protein. All of the 6 patients with del13 were IgG myeloma (2 kappa, 3 lambda). DISCUSSION AND CONCLUSION: Compared to the recent studies, del13 is lower in our study. In many studies, del13 has been found in rates ranging from 30-50%. Although the rate of 20% we found is lower than the data in the literature, it is valuable in terms of reflecting the frequency of del13 in myeloma patients. Therefore, we strongly recommend that conventional karyotyping and FISH analysis of common chromosomal abnormalities be performed in newly diagnosed MM patients.

Keywords

• multiple myeloma
• chromosome 13 deletion
• fish
• hypodiploidy