Complement Gene Mutation and Ehlers-Danlos Syndrome

Background: Dental complications of Ehlers-Danlos syndrome (EDS) include periodontitis with gum fragility and inflammation, enamel hypoplasia with frequent caries, high palate with dental crowding, TMJ instability, sutural dehiscence or scarring, and insensitivity to anesthetics. Objective: Determine if EDS dental complications always define a specific type and genetic cause or if they can arise as a general consequence of altered inflammatory response in EDS. Method: We compared findings of a 58-year-old female with complement component 1R (C1R) gene mutation (c.1553A > T, p.Asp518Val) found by whole exome sequencing to 43 patients with C1R gene mutations ascertained because of periodontal disease and to 710 EDS patients conventially ascertained because of joint and skin laxity. Result: Female patients ascertained as periodontal EDS showed the expected higher frequency of periodontitis (96% versus 14%) but had similar frequencies of hypermobility (81% versus 90%) and some skin findings (84% versus 92% with skin fragility) as the general group and our female patient who shared their C1R gene change. Her oromandibular bone loss rather than gum disease may reflect the more carboxy-terminal position of her C1R gene mutation compared to those in the patients identified as periodontal EDS. Conclusion: While mutation of the C1R gene may predict more frequent periodontal, skin, and vascular complications, focus on an articulo-autonomic dysplasia process that includes mast-cell activation and altered inflammatory response rather than extreme EDS types will help dentists and other subspecialists identify all EDS patients and anticipate their frequent oral manifestations.