Derivative chromosme 9 deletions are large, span the translocation breakpoint, and demonstrate heterogeneous deletion breakpoints. A summary of FISH mapping of 16 patients with deletions is shown. Locus-specific probes from 9q34 and 22q12 together with corresponding physical and genomic map data are shown. White boxes indicate the retention of a locus; black boxes indicate the loss of a locus; and gray boxes indicate not performed. (Adapted from Sinclair et al.³⁹ )