Genetic and structural alterations of enamel and dentin- amelogenesis imperfecta, dentinogenesis imperfecta and dentin dysplasia

The protein gene family includes extracellular molecules (ECM) proteins, responsible for dentin/bone coding (DSPP, DMP1, IBSP, MEPE, and SPP1), enamel (AMEL, ENAM, AMBN, and AMTN), as well as milk casein, and some salivary protein genes (Table 1). These molecules encompass inherited defects of dental enamel (AI) and dentin (DI and DD). They display both clinical and genetic heterogeneity. These groups include different sub-types recognized on the basis of their clinical appearance. Diseases affecting tooth structures have been classified into distinct tissues [enamel (AI) versus dentin (DI & DD), the specificity of the mutation (syndromic versus non-syndromic), and their pattern of inheritance [autosomal dominant (AD), autosomal recessive (AR), or X-linked recessive (XLR)]. Mutations in the AMELX , ENAM , MMP20 and KLK4 genes are associated with specific AI types. Another series of gene mutations influence dentin structure and composition [dentinogenesis imperfecta (DI) and dentin dysplasia (DD)]. These mutated genes are implicated in defective dental tissues.1–3