Fig. 2

G-banding and FISH information on two cellular angiofibromas. a-c: Case 1, d-f: Case 2. a Partial karyotype of case 1 showing the two normal copies of chromosome 1, a normal chromosome 13, and the der(13)t(1;13)(q12 ~ 21;q14 ~ 21). b Partial karyotype showing the normal chromosome 16 and the der(16)t(7;16)(q11;q22). c Interphase FISH showing one red signal (probe for the RB1 gene) and one green signal (probe for 13qter) in three interphase nuclei and two red and two green signals in one nucleus. d Partial karyotype of case 2 showing the normal chromosome 13 and the del(13)(q12q22). e G-banding of a metaphase spread used for FISH analysis. f FISH results with the RB1 deletion probe consisting of a 318 kb red probe spanning the RB1 gene locus and a 13qter green probe acting as a control for chromosome 13. The RB1 locus was deleted in the del(13)(q12q22). Breakpoint positions are indicated by arrows