DKC1 gene mutations in human sporadic cancer.

Summary. Introduction: Germline mutations in the tumour suppressor gene dyskeratosis congenit 1 (DKC1) cause the cancer prone syndrome called X-linked dyskeratosis congenita. The present study aims to determine whether mutations of the DKC1 gene may also be present in frequent human sporadic cancers (breast, colon and lung cancers), thus potentially contributing to the neoplastic phenotype. Materials and methods: mutation analysis of the DKC1 gene was performed on DNA from 110 primary human lung, 54 breast, and 35 colon cancers, focusing on gene regions where pathogenic germline mutations have been described previously (promoter and exons 1, 3, 9, 10, 11, and 14). Results: Out of a total of 199 primary tumours of different origins, only 5 turned out to have sequence variations in the DKC1 gene. These variations were of two kinds, C8120T and C13554T, which are both classified as synonymous mutations and do not affect DKC1 mRNA splicing. Conclusion: direct DKC1 gene mutations are not a frequent event in tumourigenesis, at least in the tumour types investigated and for the DKC1 gene portions considered in this study.