Ectodermal dysplasias (ED)
are a group of about 150 heritable disorders that affect the ectoderm, a layer of tissue that contributes to the formation of many parts of the body, including the skin, sweat glands, hair, teeth, and nails. Symptoms can range from mild to severe and may include dental abnormalities; brittle, sparse or absent hair; abnormal fingernails; inability to perspire (hypohidrosis); various skin problems; and other symptoms. Different types of ectodermal dysplasias are caused by mutations in different genes, and can be inherited in a variety of ways. There are no cures for ED, but many treatments are available to address the individual symptoms. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.