Involvement of IGH@ and CRLF2. The same metaphases from a patient with t(X;14) (A-B) and one with t(Y;14) (C-D) showing a positive result with the IGH@ probe: normal chromosome 14 (yellow arrows), derived chromosome 14 (der(14); red arrows; panels A,C); involvement of the X chromosomes (wcpX; green arrows on der(X)x2; panel B), involvement of Y chromosome (wcpY; green arrow; panel D). Representative metaphase hybridized with CRLF2 probe 1 showing the translocation (E) normal X (yellow arrow), der(14) (red arrow), der(X) (green arrow). Representative metaphase hybridized with the probe to P2RY8 showing the deletion (F): normal X (yellow arrow), X with deletion of red signal covering 3′ P2RY8 (green arrow). Magnification, ∼ × 1000. FISH probe designs for break-apart probes to CRLF2, probes 1 and 2 (G), and P2RY8 (H). (G) The red and green boxes above the schematic representation of PAR1 show the clones (Wellcome Trust Sanger Institute) used in the design of CRLF2 probe 1 (clone names given above each bar). The red and green boxes below the schematic indicate the clones (Invitrogen) used in the design of CRLF2 probe 2. (H) FISH probe design for P2RY8. Fosmid and BAC clone names are given above each bar. (I) Idiograms of X and Y chromosome showing the location of the PAR1 region. Breakpoint locations cloned by LDI-PCR from IGHJ segments are marked with red arrows.