Clinical and genetic analysis of a pedigree affected with a syndromic form of hereditary gingival fibromatosis

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