Structure and prognostic signifi cance of 13q14 deletion in chronic lymphocytic leukemia

Introduction . 13q14 deletion is the most common chromosomal abnormality in chronic lymphocytic leukemia (CLL), and as sole determines favorable prognosis of disease. Using molecular genetic methods two subtypes were identifi ed based on size lost material: small (type I) with involvement D13S319 segment containing MIR15A / MIR16-1 DLEU1 genes large II) centromeric region involving RB1 gene. Data impact type I II deletions course CLL are controversial. Aim — to evaluate prognostic signifi cance different variants CLL. Patients The study enrolled cohorts patients. Cohort 1: 256 patients who studied by FISH DNA probes for detection 13q14/D13S319, 11q23/ATM, 17p13/TP53 deletions, trisomy 12 before immunochemotherapy. 101 13q14/D13S319 analyzed a probe locus determination or II). 2: 28 at stages disease detected using combination standard cytogenetic (mFISH, mBAND, arrayCGH) clarify structure 13q abnormalities. Results In 1 aberrations 75 % patients: 52 (isolated 36 all cases 48 deletion), 11q 19 %, +12 13 17p 6 %. was 56 44 Type correlated presence (p = 0.05). Isolated found 61 39 respectively. Biallelic 12.7 deletion. Statistically cant differences OS obtained groups isolated deletions: median not reached made 67.5 months, respectively, p 0.05. 2 structural abnormalities chromosome conventional analysis (CCA) 50 cases: 11 cases; translocations cases. 5 biallelic FISH, CCA patients, only one allele. Conclusion general, factor but its heterogeneous. Loss tumor suppressor deletion) negatively affects treated immunochemotherapy