Deletion mapping on the short arm of chromosome 1 in Merkel cell carcinoma

Twenty-two Merkel cell carcinoma (MCC) biopsies and six cell lines from 24 patients were examined for loss of heterozygosity (LOH) at II loci on 1p an d one on 1q, to determine LOH regions on chromosome 1p. Sixteen (73%) tumor s had LOH for at least one locus; 14 demonstrated LOH at more than one locu s, and 7 (29%) samples had more than one region of loss, with 4 of these ha ving loss at all informative loci on 1p. Three common regions of loss (SRO) were defined by LOH in multiple tumors. Eight samples demonstrated LOH bet ween D1S214 and D1S160 (1p36), seven between D1S234 and D1S186 (1p35), and 11 for the region centromeric of D1S211 and D1S220 (1p32-1p33). Seven sampl es (29%) demonstrated more than one region of loss. LOH on 1p occurs freque ntly in MCC and more than one tumor suppressor gene on 1p is likely to play a role in the development of this tumor type.