Supplementary Material for: Molecular Analysis of Desmoid Tumors with a High-Density Single-Nucleotide Polymorphism Array Identifies New Molecular Candidate Lesions

<b><i>Background: </i></b>Desmoid tumors are neoplastic proliferations of connective tissues. The mutation status of the gene coding for catenin (cadherin-associated protein) beta 1 (CTNNB1) and trisomy 8 on the chromosomal level have been described to have prognostic relevance. <b><i>Patients and Methods: </i></b>In order to elucidate new molecular mechanisms underlying these tumors, we carried out a molecular analysis with a genome-wide human high-density single-nucleotide polymorphism (SNP) array, in 9 patients. <b><i>Results: </i></b>Single samples showed numerical aberrations on chromosomes (Chrs) 20 and 6 with either trisomy 20 or monosomy 6. No trisomy 8 could be detected. Recurrent heterozygous deletions were found in Chr 5q (including the <i>APC </i>gene locus, n = 3) and Chr 8p23 (n = 4, containing coding regions for the potential tumor suppressor gene <i>CSMD1</i>). This novel deletion in 8p23 showed an association with local recurrence. In addition, structural chromosomal changes (gain of Chrs 8 and 20) were found in a minority of cases. <b><i>Conclusion: </i></b>The genomic alteration affecting the candidate gene <i>CSMD1 </i>could be important in the development of desmoid tumors.