To explore the clinical and genetic characteristics of a Chinese pedigree affected with a syndromic form of hereditary gingival fibromatosis (HGF).

Clinical data of the pedigree members were collected. The excised gingiva were collected, and the pathological features were observed by histological sectioning. Genomic DNA was extracted from peripheral blood samples, and whole-exome sequencing was used to identify gene mutations.

The proband, her mother, her maternal grandfather and her maternal grandfather's sister all suffered from gum hyperplasia; female patients had congenital hirsutism and macromastia, while male patients also had congenital hirsutism, which suggests that this pedigree may have a congenital syndrome. The pathological characteristics of the gingival tissue were chronic inflammation with fibromatous hyperplasia, connective tissue enlargement, and filling with thick collagen fiber bundles. In addition, whole-exome sequencing results showed that no mutations related to known pathogenic genes were found, suggesting that new pathogenic gene mutations may be the cause.

According to the literature and our gene sequencing results, it is suggested that this may be the first pedigree with a new syndrome HGF (gingival fibromatosis+congenital hirsutism+macromastia) caused by an unknown pathogenic gene mutation.

To investigate the antibacterial effect of a new photosensitizer, indocyanine green (ICG)-mediated photodynamic therapy, on a biofilm of Fusobacterium nucleatum (F. nucleatum) in vitro.

The biocompatibility of the photosensitizer ICG was detected by CCK8. F. nucleatum (10⁸ CFU/mL) was cultured in anaerobic conditions (80% N₂, 10% H₂ and 10% CO₂) mixed with the photosensitizer ICG at concentrations of 0, 10, 20, 30, and 40 μg/mL and then treated with antibacterial photodynamic therapy (808 nm near infrared light with an intensity of 0.1 W/cm² for 3 min), and a mature biofilm was formed after 2 days. The bacteriostatic effects of different concentrations of ICG on F. nucleatum biofilms were compared by colony formation unit count (CFU). The effect of ICG on the formation of F. nucleatum biofilms and biofilm metabolic activity was determined by crystal violet quantification and MTT assays. The effect of ICG on the formation of extracellular polysaccharides in F. nucleatum biofilms was determined by the phenol-sulfuric acid method. The change in the number of bacteria was observed by confocal microscopy.

CFU and biomass of the biofilm gradually decreased with increasing ICG concentration, and there were significant differences compared with the control group. Meanwhile, the metabolic activity of the biofilm and the production of extracellular polysaccharides also showed a significant difference between the ICG groups and the control group (P< 0.01). At the same time, laser confocal microscopy showed that the number of living bacteria decreased gradually.

Antibacterial photodynamic therapy with photosensitizer ICG can effectively inhibit the formation of F. nucleatum biofilms.