A group of hereditary defects of either the matrix or the mineralization of enamel. The clinical features depend on which gene is defective. The enamel may be hypoplastic and appear thin or pitted; hypocalcified and appear opaque white-, honey-, or brown-coloured; or hypomatured and appear mottled or frosty-white, sometimes confined to the incisal third of the tooth (snow-capped teeth). Where there is hypocalcification, the enamel is soft and subject to excessive tooth wear. There may be symptoms of thermal sensitivity. Treatment is usually by restorative intervention. See also dentinogenesis imperfecta.