Point mutations in the DKC1 gene that encodes dyskerin cause the rare inherited 
syndrome called X-linked dyskeratosis congenita, characterized by a failure of 
proliferating tissues and increased susceptibility to cancer. Dyskerin is a 
nucleolar protein with different functions, all fundamental to basic cellular 
events such as protein expression, growth, and proliferation. The two 
best-characterized dyskerin activities are the stabilization of the telomerase 
RNA component, allowing the proper function telomerase enzymatic complex, and 
the modification of specific uridine residues of ribosomal RNA by converting 
them to pseudouridine, thus allowing proper ribosome processing and function. In 
light of the recent findings, this review focuses on the molecular pathogenesis 
of dyskeratosis congenita, discussing how a defect in ribosomal function might 
impact on the translation of a subset of mRNAs encoding for tumour suppressors, 
thus providing an explanation for the apparent paradox of dyskeratosis congenita 
in which reduced cell proliferation is associated with cancer susceptibility. In 
addition, the current evidence pointing to a role played by dyskerin in tumours 
in the general population is also discussed.