We previously identified heterozygous missense mutations in the C1R and C1S genes in patients affected by periodontal EDS (pEDS, OMIM 130080 and 617174) (2), a rare specific EDS subtype hallmarked by early severe periodontitis leading to premature loss of teeth (3), in addition to connective tissue alterations (4). This evidence concerns the gene C1R and periodontitis.