Deletions affecting the 13q14 band and trisomy of chromosome 12 are common events in B-cell Chronic Lymphocytic Leukaemia (B-CLL).
Deletions affecting the 13q14 band are the most frequent genetic abnormalities of B-CLL1. This region is found to be deleted heterozygously in 30-60%, and homozygously in 10-20%, of CLL patients2. Recently, the survival rate has been shown to be similar3. Two non-coding RNA genes, DLEU1 and DLEU2, and the genetic marker D13S319, span the pathogenic critical region 13q14.34. DLEU1 is considered to be the most likely CLL-associated candidate tumour suppressor gene within the 13q14 region5.