Physiopathology
Strikingly, these 5 genes encode components of the telomerase complex and are all required for normal maintenance of telomere lengths (telomeres are specialized structures found at the ends of chromosomes and required for their stability).
It is thus believed that Dyskeratosis Congenita arises above all from a defect in telomerase activity. In addition, Dyskerin and Nop10p are also involved in the synthesis of ribosomes, essential complexes catalyzing the synthesis of proteins.
Thus it is likely that alterations of dyskerin and Nop10p responsible for DC cases also induce ribosome synthesis defects, and hence protein synthesis defects, which increase the patients’ symptoms.
Interestingly, several constitutional bone marrow disorders (in particular, Blackfan- Diamond anemia and Shwachman-Diamond syndrome) are caused by mutations in genes encoding factors implicated in ribosome biogenesis and translation.
