Cytogenetics of chronic lymphocytic leukaemia in Malta

Abstract

Introduction: Chronic lymphocytic leukaemia (CLL) is a haematological malignancy which is commonly found in adults. It is characterized by mature B lymphocytes which accumulate in the blood. CLL has various prognostic indicators which include age, gender, chromosomal abnormalities and haematological parameters. Chromosomal abnormalities seen in CLL include c1ytpic abnormalities which require the use of molecular cytogenetic methods or molecular genetic methods for detection. Methods: Blood was collected from 21 untreated patients with CLL who consented to participate in this study. Chromosomal suspensions were prepared using standard methods in the Cytogenetic Laboratory. Fluorescence in situ hybridization (FISH) using probes specific for 17p13.1, 11q22.3, 13q14.3 & CEP 12 loci were used. The results obtained by FISH were compared with those obtained using G-banded karyotyping. Furthermore the chromosomal aberrations detected were correlated with the patients' age, gender and haematological parameters. Results: The most common chromosomal abnormality was deletion (del) 13q14x1 (40%), followed by del 17P13x1 (20%), del 11q22x1 (15%), trisomy 12 (10%) and del 13q14x2 (10%). FISH results obtained proved more robust when correlated with other prognostic indicators. The results were also compared with karyotype results seen in the Cytogenetic Laboratory. Karyotyping identified chromosomal abnormalities, which were not detected by the FISH panel but failed to identify some cryptic chromosomal abnormalities which were seen only by FISH. Conclusion: In conclusion, both FISH and karyotyping techniques are recommended in patients with CLL in the Maltese medical setting to improve patient management.