Chromosome band 1q21 is recurrently gained in desmoid tumors.

DNA sequence copy number changes were studied by comparative genomic hybridization (CGH) in 28 desmoid tumors. Changes were detected in 12 tumors (43%) with a mean of 1.4 changes per sample (range: 1 to 7). Out of 12 tumors associated with pregnancy or Gardner's syndrome, only two displayed changes. The minimal common regions of the most frequent gains were 1q21 (39%), chromosome 20 (32%), and 9p12 (21%). No high-level amplifications were detected. Losses of DNA sequences were two times less frequent than gains and the minimal common regions of the most frequent losses were 6q16-q21 (14%), 5q14 (11%), and 13q21-q31 (11%).