THE CYLINDROMATOSIS GENE (CYLD1) ON CHROMOSOME 16Q MAY BE THE ONLY TUMOR-SUPPRESSOR GENE INVOLVED IN THE DEVELOPMENT OF CYLINDROMAS

Hereditary cylindromatosis is a rare autosomal dominant disease charac terised by the development of multiple benign neoplasms of the skin, W e recently localised the gene responsible for this disease (cyld1) to chromosome 16q12-q13 and provided evidence that it is a tumour suppres sor gene (Biggs et al., 1995). We have now examined polymorphic marker s on every chromosome, some of which are close to known tumour suppres sor genes, in 25 tumours from 4 individuals with familial cylindromato sis, No loss of heterozygosity (LOH) was detected other than at loci o n chromosome 16q. This observation suggests that the cyld1 gene may be the only tumour suppressor gene implicated in the development of cyli ndromas. We have also demonstrated LOH using markers on chromosome 16q in 8/14 (57%) sporadic cylindromas, indicating that the cyld1 gene is likely to be involved in the genesis of both familial and sporadic cy lindromas.