Tom Vulliamy and colleagues, working in Paediatrics at Barts and the London, have discovered genetic mutations that may be the cause of the premature aging syndrome dyskeratosis congenita. The mutations alter the shape of a small protein, NHP2, that helps maintain telomeres, a region of repetitive DNA at the end of chromosomes that helps protect the end of the chromosome from degradation. Patients with dyskeratosis congenita have extremely short telomeres and suffer from many features of early aging, such as premature graying, dental loss, and osteoporosis. NHP2 is one of several telomerase components in which mutations have been linked to the syndrome. The authors suggest that NHP2 mutations are recessive: both parents must contribute a defective gene for the child to develop the disease. The researchers identified the mutations in a screen of 117 patients with dyskeratosis congenita. Most of the mutations so far identified in patients with classical dyskeratosis congenita impact either directly or indirectly on the stability of RNAs. In the new report, the authors suggest that human patients with NHP2 mutations have low levels of telomerase RNA in their peripheral blood, providing direct evidence of the mutations' role in telomere maintenance in humans.