Pathognomonic oral phenotypes in patients with Enamel Renal Syndrome. (A, B, C, D, E, F, G, H) Oral views and corresponding orthopantomogram of 4 unrelated ERS patients, all with recessive mutations in FAM20A. Oral view showing hypoplastic AI, delayed tooth eruption, widely spaced teeth, flat cusps of posterior teeth, upper permanent central incisor crown resorption and gingival hyperplasia. Orthopantomograms show generalized absence of enamel, altered tooth eruption pathway, flat cusps of posterior teeth (white elipse), intra-pulpal calcification (white triangle), hyperplastic dental follicles (white diamond), and gingival hyperplasia (dashed line). Semi-lunar shape of the permanent right upper central incisor, crown resorption and root dilacerations (white arrow) are also present. Note the consistent oral features in all patients. (I) Summary picture of pathognomonic oral diagnosis criteria listed in orthopantomogram.