Jumping translocation of chromosome 14 in a skin squamous cell carcinoma from a xeroderma pigmentosum patient.

The cytogenetic study of a case of cutaneous squamous cell carcinoma developed in a child affected by xeroderma pigmentosum is described. In this paratetraploid tumor, virtually all mitoses had the following rearrangements: i(1q), i(1p), t(3q14q), del(9p), and der(19)t(8;19). In addition, there were several deletions of 1p and 1q. The del(9p) likely occurred as the first rearrangement. The distal segment of the short arm of chromosome #9 and the long arm of #19 and #22 were the most underrepresented and chromosome #6 the most overrepresented chromosome or chromosome segment. The most striking anomaly detected was a jumping translocation of chromosome #14, involved with chromosomes #1, #3, #5, #7, #9, #14, and #22. The breakage of chromosome #14 always occurred on the short arm.