A number of mutations in the proteins involved in the mineralization (AMEL, AMBN, AMTN, ENAM) or the maturation processes (DSPP, KLK4, MMP20) of enamel and dentin are indeed associated with particular enamel phenotypes or tooth defects, or create susceptibility to dental disorders such as amelogenesis imperfecta (AI), dentinogenesis imperfecta (DI)/dysplasia (DD) or caries [12, 16, 35–42] (Table 1). The gene discussed is ENAM; the disease is amelogenesis imperfecta.