Ectodermal dysplasia (ED) syndrome is a rare genetic disease that involves a heterogeneous group of hereditary disorders that occur as a result of mutations in genes that code for development of fetal ectoderm and lead to numerous disorders. Defects in the development of the ectoderm cause symptoms in tissues derived from the ectoderm layer, such as skin, nails, hair, and teeth. Because many pathways are involved in the development of the ectoderm, there are mutations in many genes that cause ED. Owing to the heterogeneity of ED, there are different types of the disease that have different symptoms. These symptoms include sparse hair, abnormal or missing teeth, nail dystrophy, lack of sweating owing to the absence of sweat glands, and cancer. In this review, in addition to discussing the role and pathway of each of the genes involved in ED, the incidence of cancer in these patients, diagnostic methods and differentiation from other similar diseases, and the treatments currently being performed for ED are discussed.