UNLABELLED

Rhabdomyosarcomas (RMS) are one of the most common types of sarcomas in children and adolescents. The alveolar RMS subgroup is of particular interest because in some cases, the translocation of the and genes is combined with an amplification of the corresponding hybrid gene. According to literature data, the frequency of the translocation is 70-90% and the translocation 10-30%.

OBJECTIVE

To determine the frequency of variable translocations in the alveolar RMS patient group.

MATERIAL AND METHODS

Thirty-two tumor samples were collected and analyzed using a combination of histological, immunohistochemistry (Myogenin, MyoD1), and molecular genetic techniques (fluorescence in situ hybridization (FISH) and real-time polymerase chain reaction (RT-PCR)).

RESULTS

Cytogenetic analysis using the FISH technique with a FOXO1-specific probe identified 26 (81%) samples with rearrangements at the FOXO1 locus and seven (19%) without rearrangements. Real-time PCR identified the translocation partners in 58% (15/26) and in 42% (11/26) of samples.

CONCLUSION

Four cytogenetic patterns were observed: classical translocation, translocation with amplification, translocation with deletion, and normal signal distribution. Alveolar rhabdomyosarcomas exhibit genetic heterogeneity and a diversity of cytogenetic profiles. The frequency ratio of variable transcripts is 1:1. Approximately 20% of cases of alveolar RMS do not have cytogenetic signs of rearrangements of the gene.