Figure 2

Pericentric inversion of chromosome 5. Partial ideogram of a metaphase from the bone marrow aspirate from P2 showing both the normal and abnormal Chr5 with an inversion estimated to be between cytobands 5p15.1 and 5q13.3 (A). Schematic diagram of Chr5 showing the normal cytoband localization of the fluorescence in situ hybridisation (FISH) probes RP11-211K15 and RP11-422I12 (B). RP11-211K15 maps to an intergenic region at 5p15.1. RP11-422I12 maps to 5q14.1, and spans intron 1 to intron 16 of AP3B1. FISH was performed on metaphase chromosomes from P2, who was a heterozygote carrier of the inverted Chr5 (C and D). The images show DAPI stained chromosomes labelled with pGA-16 (green signal) which is a centromere marker of Chr5 and Chr9. The 5p15.1 probe RP11-211K15 (C; red signal) correctly localises to 5p15.1 in the normal Ch5 (solid arrow) but showed dual hybridisation to 5q14.1 and 5p15.1 in the inverted Chr5 (broken arrows). The 5q14.1 probe RP11-422I12 (D; red signal) correctly localises to 5q14.1 in the normal Ch5 (solid arrow) but showed dual hybridisation to 5p15.1 and 5q14.1 in the inverted Chr5 (broken arrows).