Prevalence and clinical correlates of JAK2 mutations in Down syndrome acute lymphoblastic leukaemia

Br J Haematol. 2009 Mar;144(6):930-2. doi: 10.1111/j.1365-2141.2008.07552.x. Epub 2008 Dec 20.


Recurrent, prognostically significant chromosomal abnormalities occur in approximately 75% of paediatric acute lymphoblastic leukaemia (ALL), but only infrequently in children with Down syndrome (DS) and ALL. Recently, novel somatic activating mutations in the gene Janus kinase 2 (JAK2) were reported in 18% of DS ALL. Here we report identification and clinical correlates of JAK2 mutations in an independent cohort. JAK2 activating mutations occurred in 10/53 DS ALL cases (18.9%). Mutations were overrepresented in males (P < 0.03), occurred once in association with high hyperdiploidy and were not significantly correlated with age, initial white blood count, or event-free survival. Our results confirm the significance of JAK-STAT pathway activation in DS ALL.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Child
  • Child, Preschool
  • Diploidy
  • Disease-Free Survival
  • Down Syndrome / complications*
  • Down Syndrome / genetics
  • Down Syndrome / mortality
  • Enzyme Activation / genetics
  • Humans
  • Janus Kinase 2 / genetics*
  • Janus Kinase 2 / metabolism
  • Kaplan-Meier Estimate
  • Male
  • Point Mutation*
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / enzymology
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / genetics*
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma / mortality
  • Sequence Analysis, DNA
  • Sex Factors


  • Janus Kinase 2