Mutation frequencies of SF3B1 (9·7%), NOTCH1 (8·6%), BIRC3 (1·1%), ATM (16·9%) or TP53 (8·1%), and frequencies of cytogenetic abnormalities including trisomy 12 (18·6%), del(17p) (10·4%), del(13q) (43·7%) and IGH translocation (10·1%) were comparable to those reported from Western countries, except del(11q) (6·9%) which was lower in our patients.
Prognostic factors such as chromosome abnormalities (trisomy 12, 11q deletions and 17p deletions), β2 microglobulin, thymidine kinase, CD38 and ZAP-70 expression, IGHV mutation status, and mutations in genes such as NOTCH1, MYD88, SF3B1, and ATM are also predictors of prognosis.
Whilst detection of recurrent cytogenetic aberrations and determination of the immunoglobulin heavy variable gene somatic hypermutation status have an established role in outcome prediction, next-generation sequencing has recently revealed novel mutated genes with clinical relevance (e.g.NOTCH1, SF3B1 and BIRC3).
IGHV-mutated cases were significantly more frequent among cMBLs (P = 0.005), whereas the distribution of CD38 and ZAP-70 positive cases, of patients with NOTCH1 and SF3B1 mutations or exhibiting the major CLL cytogenetic abnormalities, was similar in the two groups.