As newborns, children with progeria usually appear normal. However, within a year, their growth rate slows and they soon are much shorter and weigh much less than others their age. While possessing normal intelligence, affected children develop a distinctive appearance characterized by baldness, aged-looking skin, a pinched nose, and a small face and jaw relative to head size. They also often suffer from symptoms typically seen in much older people: stiffness of joints, hip dislocations and severe, progressive cardiovascular disease. Most kids with progeria do not live past the age of 13. There is an increased tendency to develop heart disease, diabetes mellitus, and cancer, and the average life span is 47 years. Werner syndrome is caused by mutations in the gene WRN (Werner syndrome, RecQ helicase-like). This type of progeria is hereditary and is transmitted as a recessive trait(two copies of the mutated gene, one from each parent, are required to cause the disease).