Telomere dysfunction in human diseases: the long and short of it!

It has been over one hundred years since the first reported case of dyskeratosis congenita (DC) and over twenty since the discovery of telomerase, an enzyme that adds telomeric DNA repeats to chromosome ends. Emerging evidence suggests that telomere dysfunction plays an important role in the pathogenesis of DC and other human disorders involving tissues that require rapid repair and renewal capacities. Yet we still do not fully understand how mutations in telomere maintenance genes contribute to disease development in affected individuals. In this review, we provide an up-to-date summary of the topic by discussing the results from genetic screens of patients, in vitro mutational analysis of involved molecules, and genetically engineered mouse models. While these data shed important light on the mechanisms underlying disease development, further investigation, particularly in an in vivo setting, is needed.