Royal College of Surgeons in Ireland
Fogarty et al NOTCH1 Paper IJMS.pdf (654.85 kB)

Biclonal lymphoproliferative disorders: another association with NOTCH1-mutated chronic lymphocytic leukaemias

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journal contribution
posted on 2021-11-11, 09:46 authored by Helen FogartyHelen Fogarty, Anita Dowling, David O’Brien, Steve Langabeer, Christopher L Bacon, Richard Flavin, Michael O’Dwyer, Brian Hennessy, Hilary O’Leary, Gerard Crotty, Robert Henderson, James Nolan, Patrick ThorntonPatrick Thornton, Elisabeth Vandenberghe, Fiona Quinn

Introduction: Biclonal lymphoid disorders, when two distinct lymphoproliferative disorders (LPD) co-exist, are rare (incidence of 1.4%) and associated with a poor prognosis. NOTCH1 mutations occur in 10% of CLL at diagnosis, associated with a short disease-free interval and increased risk of Richter's transformation. We hypothesised that the incidence of NOTCH1 mutations in CLL with a second LPD may be increased, because the mutation occurs early in leukaemogenesis, permitting clonal divergence.

Methods: We identified 19 patients with biclonal LPD at diagnosis: 11 with CLL and a second LPD (group A) and 8 with a second distinct CLL (group B). NOTCH1 mutation analysis was performed and clinical outcome investigated.

Results: Ten of 19 (52%) were NOTCH1 mutated: 5 in group A (45%) and 5 in group B (62.5%) with a favourable clinical outcome observed among this cohort with 28.7 (range 1-99) months of follow-up.

Conclusion: In conclusion, we identified a significant (52%) incidence of NOTCH1 mutations in CLL in the context of biclonal LPD, associated with an indolent clinical course.



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Published Citation

Fogarty H. et al. Biclonal lymphoproliferative disorders: another association with NOTCH1-mutated chronic lymphocytic leukaemias. Ir J Med Sci. 2021;190(3):1087-1094.

Publication Date

17 October 2020

PubMed ID



  • Beaumont Hospital
  • Irish Centre for Vascular Biology
  • School of Pharmacy and Biomolecular Sciences




  • Accepted Version (Postprint)