Isolation of chromosome-specific DNA sequences from an Alu polymerase chain reaction library to define the breakpoint in a patient with a constitutional translocation t(1;13) (q22;q12) and ganglioneuroblastoma

We describe the cytogenetic and molecular characterization of a t(1;13)(q22;q12) constitutional rearrangement occurring in a patient with a relatively benign form of neuroblastoma, called ganglioneuroblastoma. Somatic cell hybrids were generated between mouse 3T3 cells and a lymphoblastoid cell line from this patient, D.G. One isolated subclone, DGF27C11, contained the derivative chromosome, 1pter-q22::13q12-qter, but no other material from either chromosome 1 or 13. Using available DNA probes the 13 breakpoint was assigned proximal to all reported markers. In order to generate flanking markers to define this translocation further, an Alu polymerase chain reaction library was constructed from a somatic cell hybrid containing only the proximal, 13pter-13q14, region of chromosome 13. Seven unique sequences have been isolated from the library, three of which lie below and four of which lie above the 13q12 breakpoint. More precise mapping of the distal markers was achieved using a panel of somatic cell hybrids with overlapping deletions of chromosome 13. The paucity of probes in the 1q22 region has made a precise assignment of this breakpoint difficult, however it has been shown to lie distal to c-SKI and proximal to APOA2. This refined characterization of the breakpoint is a prerequisite for its cloning, which may yield genes important in the pathogenesis of ganglioneuroblastoma.