Dyskeratosis congenita (DC) is an inherited disorder that affects the skin, mouth, and nails, among other parts of the body. These symptoms can appear at different ages and in different combinations. Typically individuals with DC will develop a lacy-looking discoloration on the face, neck and chest, white patches in the mouth and will have fingernails and toenails that are shaped abnormally. They may have eye or dental abnormalities, hair loss, short stature and a small head. Some may have a variable amount of delay of developmental skills. Individuals affected with DC are at an increased risk of developing certain life-threatening conditions, which include bone marrow failure, some forms of blood cancer and other cancers, and pulmonary fibrosis, a condition where scar tissue builds up in the lungs and reduces the amount of oxygen transported into the bloodstream. Intellect is usually normal in affected individuals. Life expectancy is not significantly shortened by DC. There is no cure for DC, but medical care and surveillance may help to improve some symptoms and overall condition of life. One of the causes of DC is pathogenic variants in the RTEL1 gene.