The epigenetics of enamel formation

Amelogenins, a family of enamel extracellular matrix proteins, are abundantly expressed during tooth development. It is produced by the AMELX Xq22 and AMELY Yp11 genes and the level of transcription of AMELY locus appears to be only approximately 10% of amelogenin transcripts. DNA methylation is the major epigenetic mechanism of regulation of gene expression. Many factors can interfere in gene silencing, such as polymorphisms and nutrients and some genes escape inactivation, principally X-linked genes. The large number of genes that escape inactivation, and their non-random distribution on the chromosome X may have implications in abnormalities caused by genes on this chromossome. Defects of dental enamel formation are caused by genetic or environmental factors, including genetic polymorphisms and nutrient intake. However, the relationship between epigenetic and genetic factors in amelogenesis is not known. In this context, DNA methylation might be a promising path to explain not only the mechanisms of AMEL inactivation, but also in pathological situations.