FISH analysis demonstrating recurrent involvement of

BCL11A in cases with t(2;14)(p13;q32.3). (A) mBAC RP11-440P05 (AC009970) (red signal) hybridized to metaphases derived from a healthy individual maps to chromosome region 2p13. A centromeric probe for chromosome 2 (green) is also shown. (B) FISH with RP11-440P05 (red) on a t(2;14)(p13;q32.3) positive metaphase from patient 4. Apart from the intact chromosome 2, signals for the BAC were detected on both derivative chromosomes, indicating that it spanned the breakpoint. Inset: FISH with cosIgCα1 (green) hybridizing to theIGH-locus and RP11-440P05 (red signal) on interphase cells from patient 4. The cell lacking the translocation contains 2 isolated red and green signals. The fusion signal in the other cell represents the der(14) t(2;14)(p13;q32.3). The minor signal remaining on the der(2) chromosome could not be detected reliably in interphase cells. (C) FISH with pooled BCL11A-specific clones RP11-440P05 and RP11-158I21 (green AC007831) and 2 pooledREL-specific YAC clones 747H5 and 927G9 (red) on interphase nuclei of patient 3 with t(2;14)(p13;q32.3). On an intact chromosome 2 the REL- and BCL11A-specific signals colocalized. Translocation led to the disruption of the greenBCL11A-specific signal with a minor part remaining colocalized with the REL-signal on the der(2) and the major part on the der(14) separated from the REL-specific signal. (D) Southern blot analysis of t(2;14)(p13;q32.3) from patient 3. DNA from patient 3 digested with HindIII and probed withIG 3′Sγ probe and derived 2p13 breakpoint probe, EH3.0P31 showing comigration of one rearranged Sγ and 5′BCL11A sequences in this case. Left lane denotes control DNA; right lane, DNA from patient 3.