Evaluation of the Sensitivity of Conventional Cytogenetic and Fluorescence in Situ Hybridization Methods for the Detection of Cytogenetic Abnormalities in Multiple Myeloma Patients: A Retrospective Study

Background: Identification of genetic abnormalities in multiple myeloma (MM) patients is of particular importance in order to design their treatment and management. Therefore, it is necessary to use the diagnostic methods with high sensitivity to detect abnormalities. In this study, we investigated the sensitivity of conventional cytogenetic and FISH methods in the diagnosis of genetic abnormalities in MM patients. Methods: This retrospective study included 246 patients who referred to the Kariminejhad Center for the Diagnosis of Genetic Abnormalities between 2009-2019. All patients were diagnosed based on diagnostic tests, as well as the approval of the relevant physician. The diagnosis of cytogenetic abnormality was made based on the two methods of conventional cytogenetic and FISH. Result: The results showed that out of 246 patients examined by conventional cytogenetic, only 17.8% had abnormal karyotypes. While out of 67 patients examined by FISH, 64.1% had abnormal results. The results also showed that 31 out of 50 patients with normal karyotype had abnormal FISH result. In the present study, the results showed that 25% of the patients had hyperdiploidy (57-47), which was diagnosed by conventional cytogenetic. Also, 40.90% had diploid abnormalities (pseudodiploid or structural abnormalities). FISH detected del 13q in 27.9% and t(11;14) IGH-CCND1 in 18.6% of patients, which were the most frequent compared to other abnormalities. Conclusion: Considering that the variety of mutations and translocations is high in different parts of the world and every day new mutations are detected, using both methods together can help to identify genetic disorders.