Cytogenetic and FISH analysis of 93 multiple myeloma Moroccan patients

• Published in: Molecular genetics & genomic medicine 2020-09, Vol.8 (9), p.e1363-n/a
• Main Authors: Hamdaoui, Hasna, Benlarroubia, Oumaima, Ait Boujmia, Oum Kaltoum, Mossafa, Hossein, Ouldim, Karim, Belkhayat, Aziza, Smyej, Imane, Benrahma, Houda, Dehbi, Hind, Chegdani, Fatima
• Format: Article
• Language: English
• Subjects: Abnormalities; Age; Anemia; Anomalies; Bone marrow; Cancer; Cell proliferation; Chromosome aberrations; Chromosome deletion; Chromosome translocations; Chromosomes; conventional karyotype; cytogenetic; Cytogenetics; Deletion; FISH; Flow cytometry; Fluorescence; Fluorescence in situ hybridization; Gender; Genetic abnormalities; Genetics; Heavy chains; Hybridization; Immunoglobulins; Karyotypes; Laboratories; Multiple myeloma; Original; Plasma; Plasma cells; plasma cells sorted; Statistical analysis; Translocation
• ISSN: 2324-9269; 2324-9269
• DOI: 10.1002/mgg3.1363

Background Multiple myeloma (MM) is a disease characterized by heterogeneous clinical presentations as well as complex genetic and molecular abnormalities. In MM, cytogenetic analysis is a challenge because of the low proliferation of malignant plasma cells. Thus, interphase fluorescence in situ hybridization (FISH), performed on sorted plasma cells detected abnormalities independently of a proliferative and infiltrative index. The purpose of this study was to explore, for the first time, the cytogenetic and molecular genetics features in Moroccan patients with multiple myeloma referred exclusively to National Reference Laboratory and to determine their risk stratification based on these features. Methods We performed cytogenetic analysis on 93 MM cases, all patients were subjected to FISH analysis, among which 45 patients have benefited from both FISH analysis and standard karyotype. Results Karyotype was normal in 78% (35/45) while, it was complex with varied structural and numerical abnormalities in 22% (10/45) of all patients, among which Hyperdiploid karyotype was found in 9% (n = 4 cases) and nonhyperdiploid in 13% (n = 6 cases). The most common numerical abnormalities were gains of chromosomes 3, 5, 9, 15, and 19. Whole chromosome losses were also frequent, affecting chromosomes X, 3, 14, 16 and 22. FISH analysis detected abnormalities in 50% of cases. The translocation t(4;14) and dup (1q) were the most frequent types of anomalies (14% and 13% respectively), followed by (17p) deletion and 14q32/IGH translocations with an undetermined origin (12% each) then the (1p) deletion (4%). For the normal karyotypes, FISH revealed chromosome abnormalities in 46%. Conclusion This study compares the results of cytogenetic analysis of chromosomal abnormalities in the Moroccan population with other countries. ½ patient showed at least one type of molecular genetic abnormalities. Therefore, the introducing of the cytogenetic analysis is obligatory in the diagnosis of multiple myeloma. It's the first study of its kind, which studies the cytogenetic profile of multiple myeloma on Moroccan patients. In order to determine the frequency of the most recurrent anomalies in our population and their risk stratification based on these features.