Figure 2

Cytogenetic analyses of cases 1 and 2. (a) Representative karyotype of case 1: 47,XY,der(2)t(2;10)(p23;q22)t(10;?)(q23;?),+der(?2)del(2)(q12)t(2;?)(p23;?),−9,der(10)t(2;10)(p23;q22),+der(?)t(9;?)(?q13;?) (arrowheads indicate breakpoints). (b) FISH analysis of a destained metaphase cell from case 1 with the ALK break-apart probe demonstrating a translocation of the orange distal (3′) to ALK signal to chromosome 10 (orange arrowhead) with retention of the green proximal (5′) to ALK signal on the der(2)t(2;10), (green arrow). A green signal is also seen on the der(?2)del(2) (white arrowhead). A fused orange–green signal is visible on the normal chromosome 2 homolog (yellow arrowhead). (c) Rearrangement of the ALK locus in an interphase cell from case 1 represented by the split orange and green signals. (d) FISH analysis of a destained metaphase cell from case 1 with a chromosome 10 CEP probe (aqua) and the VCL–ALK dual-fusion probe set confirming the presence of an orange–green fusion signal on der(2)t(2;10) (yellow arrow) and der(10) (white arrow) chromosomes. The VCL (orange) and the ALK (green) probe signals can be seen on the normal chromosomes 10 and 2, respectively. (e) Interphase FISH with the VCL–ALK dual-fusion probe set in case 1 showing the presence of two VCL–ALK fusions (juxtaposed orange and green signals). (f) Partial karyotype and schematic illustration of the chromosome 2 pericentric inversion identified in the lymph node metastasis of case 2 [inv(2)(p23q11.2)]. (g) The interphase nuclei of the primary renal tumor of case 2 negative for an ALK rearrangement (orange and green signals remain fused).