Rearrangement of the CRLF2 (Xp22/Yp11) gene is associated with poor outcome in pediatric B-progenitor and Down syndrome-associated acute lymphoblastic leukemia (ALL).
CRLF2-IGH fusions between Xp22-14q32 or Yp11-14q32 results in a deregulated expression of the cytokine receptor gene (CRLF2). This can also be the result of the fusion with the P2RY8 promoter on Xp22 or Yp11.
Gain of chromosome X has been observed in Down syndrome-associated ALL.
Mullighan et al., 2009, Nat. Genet. 41(11): 1243-1246
Russell et al., 2009, Blood, 114(13): 2688-2698