Introduction. Age is one of the important predictive factors in acute myeloid leukemias (AML), regardless of other factors. A certain dependence has been described between age and the registration of chromosomal abnormalities, namely: the frequency and spectrum of identified quantitative and structural rearrangements, especially with adverse cytogenetic prognosis, increase with the age of patients. As of now, the characteristics of the age distribution of the frequency of both cytogenetically normal karyotypes and karyotypes with quantitative and/or structural abnormalities have not been determined in Ukraine.

The aim of the study was to determine the characteristics of the distribution of quantitative and structural chromosome anomalies in different age groups of patients at the time of the diagnosis of AML. Materials and methods.

Materials and methods. Cytogenetic studies were performed on bone marrow cells from 263 patients at diagnosis AML, who were admitted to the laboratory from 2015 to 2025. The patients were divided into four age groups: I) 18 – 35 years; II) 36 – 50 years; III) 51 – 65 years; IV) patients older than 66 years. The preparations of metaphase chromosomes were made according to a generally accepted methodology and stained for G-banding. At least 20 metaphase spreads were analyzed for each patient.

Results. According to the results of karyotyping, abnormal karyotypes were found in 61.2%, with the largest group (42.9%) consisting of patients over 50 years old. A high percentage of abnormal karyotypes was recorded in the I and IV age groups (69.3% and 65.5%, respectively). Abnormal karyotypes with 1-2 chromosome rearrangements dominated in all age groups. In patients over 50 years old, the percentage of complex karyotypes was 27.3%. The frequency of registration of unbalanced chromosomal anomalies increased with age (from 47.5% in group I to 73.7% in group IV). Balanced translocations were found in all four age groups: 33.9%, 41.2%, 16.0%, and 15.7%, respectively. The highest percentage of marker and ring chromosomes was found in group IV (26.3% and 10.5%, respectively). The t(15;17) translocation was more frequently registered in patients of age groups I and II (16.9% and 17.6%, respectively). Translocations involving chromosome 11 at the locus 11q23 were found only in group III – 3.7%. In all age groups, a high percentage of karyotypes were recorded, classified as intermediate prognosis group (53.3%, 60.0%, 52.9%, and 42.3%, respectively). Moreover, an increase in the frequency of karyotypes belonging to the unfavorable cytogenetic prognosis group was observed with age of the patients, namely: from 33.3% in group I patients to 50.0% in group IV.

Conclusions. In all four age groups, karyotypes with 1 and 2 chromosomal anomalies predominated (80.8%, 81.1%, 67.9%, and 88.2%, respectively). An increase in the frequency of unbalanced chromosomal anomalies was established with the increase in patient age (from 47.4% in group I to 73.7% in group IV); in group IV, an increase in the frequency of marker and ring chromosomes was recorded (26.3% and 10.5%, respectively). Summarily, in groups I and II, balanced translocations were found in 37.3%. In all groups, the intermediate prognosis group was registered more frequently. An increase in the frequency of unfavorable prognosis from age group I to IV was noted (33.3%, 34.7%, 41.1%, and 50.0%).

Keywords: acute myeloid leukemias, quantitative and structural chromosome abnormalities, ages peculiarities.