Remarkably, about 30% of the proteins from genes present in regions associated with DD belong to five homologous superfamilies [P-loop containing nucleoside triphosphate hydrolase (also known as P-loop_NTPase), immunoglobulin-like fold, zinc finger C2H2 superfamily, zinc fingerRING/FYVE/PHD-type, and protein kinase-like domain superfamily]. This evidence concerns the gene PDC and dentin dysplasia.