Hutchinson-Gilford Progeria Syndrome and Werner syndrome, also known as 
childhood- and adulthood-progeria, respectively, represent two of the best 
characterized human progeroid diseases with clinical features mimicking 
physiological aging at an early age. The discovery of their genetic basis has 
led to the identification of several gene mutations leading to a spectrum of 
progeroid phenotypes ranging from moderate and mild-severe to very aggressive 
forms. In parallel, the creation of disease registers and databases provided 
available data for the design of relatively large-scale epidemiological studies, 
thereby allowing a better understanding of the nature and frequency of the 
premature aging-associated signs and symptoms. The aim of this article is to 
review the most recent findings concerning the epidemiology of premature aging 
disorders, their genetic basis, and the most recent reports on the frequency of 
associated diseases.