The Center for Precision Diagnostics researchers, in collaboration with Austrian, Swedish and UK geneticists, recently identified that the cause of the periodontal form of Ehlers-Danlos syndrome (EDS type VIII) results from a mutation in one of an unexpected pair of genes, C1S or C1R. Both genes dictate the synthesis of complement, a protein that plays a role in fighting infection and moving foreign cells out the cell. Most other forms of EDS are caused by sequence variants in collagen proteins. A C1S or C1R gene sequence abnormality leads to a dominant form of EDS type VIII , causing aggressive periodontitis and tooth loss at a young age. The surprising discovery accomplished by exome sequencing research is opening the door to learn how the disease progresses, a necessary step for considering treatment. Read the details of the research in the American Journal of Human Genetics.