Jumping end-to-end dicentrics in a case of squamous cell carcinoma from a patient with xeroderma pigmentosum.

Cytogenetic studies of a skin squamous cell carcinoma from a xeroderma pigmentosum patient were performed at several passages. They show the existence of recurrent rearrangements: 53% were dicentrics, of which 67% were of the telomere-telomere type. The telomeric region of the long arm of chromosome 12 was the most involved (in 38% of dicentrics), followed by 22p. The origin of this type of jumping rearrangement and its possible role on cell proliferation are discussed.