A retrospective analysis of spontaneous chromosomal aberrations in human lymphocyte cultures of individuals from Bosnia and Herzegovina

Spontaneous chromosomal aberrations are structural or numerical changes of chromosomes that occur naturally, without exposure to external genotoxic factors. They are not inherited, occur randomly in the karyotype, and do not have direct clinical significance. However, they can affect genomic instability and disease predisposition. They can result from DNA replication or repair processes errors, and typically are observed in cells that are actively dividing. Spontaneous chromosomal aberrations may arise due to the natural chromosomal instability and can be elevated in individuals exposed to mutagens. We analyzed frequencies of spontaneous chromosomal aberrations in 137 individuals subjected to karyotype analysis at the Laboratory for Cytogenetics and Genotoxicology, University of Sarajevo – Institute for Genetic Engineering and Biotechnology, during 2008-2023. Whole blood samples were cultivated for 72 hours with the thymidine added in the 48th hour. Metaphases were arrested by colcemid 60 minutes before harvesting. GTG banding was performed and slides were analyzed under 1000x magnification in accordance with An International System for Human Cytogenetic Nomenclature and E.C.A. Cytogenetic Guidelines and Quality Assurance. Constitutionally aberrant karyotypes were found in 2.92% of analysed individuals as well as altered karyotypes considered as normal chromosomal variants. In the total of 3092 analyzed metaphases, 20 spontaneous chromosomal aberrations were found in 13 individuals. This study contributes to the limited knowledge of the cytogenetic status of the Bosnian and Herzegovinian population. Further monitoring of spontaneous chromosomal aberrations incidences is recommended.