Current concepts on gingival fibromatosis-related syndromes

Zimmermann-Laband syndrome-associated hereditary gingival fibromatosis

Hereditary gingival fibromatosis (HGF) is an uncommon slow-growing fibrous overgrowth characterized by connective tissue accumulation. It presents as an isolated feature or as a manifestation of any syndrome. Various syndromes associated with HGF are inherited by autosomal dominant/recessive/X-linked traits. Zimmermann-Laband syndrome (ZLS) is a rare, autosomal dominant inherited disease manifested with gingival fibromatosis (GF), nose and ears abnormalities, and hypoplastic/dysplastic nails or terminal phalanges of hand and feet. Although the pattern of inheritance was found to be both autosomal dominant and recessive traits, the molecular basis is still unclear. This report presents a possible case of ZLS-associated HGF in a 25-year-old female patient who presents with GF, hypertrichosis, and other syndrome-related features. Her father was similarly affected whereas her mother and sibling were asymptomatic. The patient and her family members were explained about the condition and surgical periodontal therapy was carried out for the patient to improve esthetics and was followed up regularly. Esthetics was significantly improved and no recurrence was noted at the end of 6 months.

Double heterozygous pathogenic mutations in KIF3C and ZNF513 cause hereditary gingival fibromatosis

Hereditary gingival fibromatosis (HGF) is a rare inherited condition with fibromatoid hyperplasia of the gingival tissue that exhibits great genetic heterogeneity. Five distinct loci related to non-syndromic HGF have been identified; however, only two disease-causing genes, SOS1 and REST, inducing HGF have been identified at two loci, GINGF1 and GINGF5, respectively. Here, based on a family pedigree with 26 members, including nine patients with HGF, we identified double heterozygous pathogenic mutations in the ZNF513 (c.C748T, p.R250W) and KIF3C (c.G1229A, p.R410H) genes within the GINGF3 locus related to HGF. Functional studies demonstrated that the ZNF513 p.R250W and KIF3C p.R410H variants significantly increased the expression of ZNF513 and KIF3C in vitro and in vivo. ZNF513, a transcription factor, binds to KIF3C exon 1 and participates in the positive regulation of KIF3C expression in gingival fibroblasts. Furthermore, a knock-in mouse model confirmed that heterozygous or homozygous mutations within Zfp513 (p.R250W) or Kif3c (p.R412H) alone do not led to clear phenotypes with gingival fibromatosis, whereas the double mutations led to gingival hyperplasia phenotypes. In addition, we found that ZNF513 binds to the SOS1 promoter and plays an important positive role in regulating the expression of SOS1. Moreover, the KIF3C p.R410H mutation could activate the PI3K and KCNQ1 potassium channels. ZNF513 combined with KIF3C regulates gingival fibroblast proliferation, migration, and fibrosis response via the PI3K/AKT/mTOR and Ras/Raf/MEK/ERK pathways. In summary, these results demonstrate ZNF513 + KIF3C as an important genetic combination in HGF manifestation and suggest that ZNF513 mutation may be a major risk factor for HGF.

Modified gingivoplasty for hereditary gingival fibromatosis: two case reports

Background

Hereditary gingival fibromatosis (HGF) is characterized by sub-epithelial fibromatosis of keratinized gingiva resulting in a fibrotic enlargement of keratinized gingiva. The treatment choice is gingivectomy, which can be performed with an internal or external bevel incision conventionally. However, both techniques can hardly resume the natural status of gingiva, and have a certain recurrence rate, especially in the cases which have limited width of attached gingiva.

Case description

Two cases of HGF with the chief complaint of difficulty in mastication, pronunciation, and poor esthetics were presented. After the initial periodontal therapy, a novel gingivoplasty modified with a crevicular incision was applied. A full thickness flap above the mucogingival junction and a split flap below the junction were raised. Then, fibrotic connective tissue was completely eliminated and keratinized gingival epithelium was preserved. The fibrotic alveolar bone was shaped by handpiece and bur. Finally, the flap was apically repositioned and sutured. Twelve months after surgery, the gingiva recovered with normal color, contour and consistency.

Conclusions

Compared to traditional gingivectomy, modified gingivoplasty which focuses on eliminating pathological fibrotic connective tissue can completely resume the natural appearance of gingiva and demonstrate no tendency of recurrence.

A novel gene ZNF862 causes hereditary gingival fibromatosis

Hereditary gingival fibromatosis (HGF) is the most common genetic form of gingival fibromatosis which is featured as a localized or generalized overgrowth of gingivae. Currently two genes (SOS1 and REST), as well as four loci (2p22.1, 2p23.3–p22.3, 5q13–q22, and 11p15), have been identified as associated with HGF in a dominant inheritance pattern. Here, we report 13 individuals with autosomal-dominant HGF from a four-generation Chinese family. Whole-exome sequencing followed by further genetic co-segregation analysis was performed for the family members across three generations. A novel heterozygous missense mutation (c.2812G > A) in zinc finger protein 862 gene (ZNF862) was identified, and it is absent among the population as per the Genome Aggregation Database. The functional study supports a biological role of ZNF862 for increasing the profibrotic factors particularly COL1A1 synthesis and hence resulting in HGF. Here, for the first time we identify the physiological role of ZNF862 for the association with the HGF.

Hereditary gingival fibromatosis in children: a systematic review of the literature

OBJECTIVES

Hereditary gingival fibromatosis (HGF) is an uncommon, inherited condition with slow and progressive fibrous hyperplasia of the gingiva. Due to its association with mastication, speech, and occlusion problems, early diagnosis is important. We sought to summarize the available data regarding the epidemiology, clinical characteristics, and outcomes of children with HGF (< 18 years).

METHODS

A systematic literature review of the MEDLINE and Cochrane Library databases was conducted with respect to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (end-of-search date: March 1, 2019).

RESULTS

A total of 99 articles reporting on 146 patients were included. The mean age was 10.82 ± 3.93 years, and generalized gingival enlargement was seen in 97.16% (95% CI 92.69 to 99.14). Jaw, gingival, and teeth abnormalities; poor oral hygiene; eating; or speech difficulties were typical HGF-induced, while 60.90% had extraoral manifestations (95% CI 52.41 to 68.78). The disease was most commonly inherited in an autosomal dominant manner (88.41%, 95% CI 78.5 to 94.26), and about one-third of the patients had syndromic HGF (33.85%, 95% CI 23.50 to 46.00). Gingivectomy was performed in the majority of cases (91.15%, 95% CI 84.31 to 95.29), and recurrence was seen in 33.85% (95% CI 23.50 to 46.00).

CONCLUSION

HGF should be suspected in children with nodularity and gingival fibrosis, teeth abnormalities, or jaw distortion. Family history can help to establish the diagnosis.

CLINICAL RELEVANCE

More cases should focus on longer-term follow-up after gingivectomy as disease recurrence is not uncommon.

Nonsyndromic hereditary gingival fibromatosis: Characterization of a family and review of genetic etiology

Our aim is to describe a family with a nonsyndromic form of hereditary gingival fibromatosis (HGF) and discuss genetic characteristics of this rare disease by reviewing reported cases. A mother and three descendants were diagnosed with HGF. There was marked variable expressivity: from severe generalized gingival overgrowth in a 16-year-old boy (the proband) to minimal manifestations in the mother. The proband was submitted to gingivectomy and gingivoplasty. In younger siblings, the disease remained stable for 5 years, suggesting that clinical surveillance is a good option. The diagnosis was supported by histopathological examination. Analysis of this family and literature-reported cases supports that HGF most frequently shows an autosomal dominant inheritance with high penetrance and variable expressivity. Neomutations and gonadal mosaicism do not seem to be a rare event. Although five loci have been mapped by linkage analysis, only two genes, SOS1 and REST, were identified in four families.

Characterization of mesenchymal stem cells in mucolipidosis type II (I-cell disease)

Mucolipidosis type II (ML-II, I-cell disease) is a fatal inherited lysosomal storage disease caused by a deficiency of the enzyme N-acetylglucosamine-1-phosphotransferase. A characteristic skeletal phenotype is one of the many clinical manifestations of ML-II. Since the mechanisms underlying these skeletal defects in ML-II are not completely understood, we hypothesized that a defect in osteogenic differentiation of ML-II bone marrow mesenchymal stem cells (BM-MSCs) might be responsible for this skeletal phenotype. Here, we assessed and characterized the cellular phenotype of BM-MSCs from a ML-II patient before (BBMT) and after BM transplantation (ABMT), and we compared the results with BM-MSCs from a carrier and a healthy donor. Morphologically, we did not observe differences in ML-II BBMT and ABMT or carrier MSCs in terms of size or granularity. Osteogenic differentiation was not markedly affected by disease or carrier status. Adipogenic differentiation was increased in BBMT ML-II MSCs, but chondrogenic differentiation was decreased in both BBMT and ABMT ML-II MSCs. Immunophenotypically no significant differences were observed between the samples. Interestingly, the proliferative capacity of BBMT and ABMT ML-II MSCs was increased in comparison to MSCs from age-matched healthy donors. These data suggest that MSCs are not likely to cause the skeletal phenotype observed in ML-II, but they may contribute to the pathogenesis of ML-II as a result of lysosomal storage-induced pathology.

Clinical and Molecular Study of ELMO-2-Related Massive Intraosseous Vascular Malformations: Lessons Learned From 25 Years of Follow-up

Massive intraosseous vascular malformations, a relatively rare entity in the vascular malformation spectrum, deserves attention as involving the membranous bones of the craniofacial skeleton and may lead to severe life-threatening hemorrhages and even death. The main aim of this study was to summarize the 25 years of clinical experience with these vascular malformation osseous patients, focus on the molecular and genetic aspect of the clinical entity, and to emphasize the certain challenging conditions in the treatment of these patients. All the patients appeared to be unaffected at birth, whereas initial symptoms occasionally began with painless swelling in the mandible in early childhood. The disease was progressive in behavior especially in the pubertal ages and was specifically involving the maxilla and mandible of the craniofacial skeleton in all the patients. Calvarium and cranial base were the second most common involved regions among these patients (62.5%). Clavicular (50%), costal (25%), and vertebral (25%) involvements were also a significant manifestation of the disease. Tissue samples obtained from the affected individuals and the blood samples from their families were matched, revealing a loss of function mutation in the ELMO-2 gene of chromosome 20 leading to developmental abnormality of the vascular structures via RAC1 signaling and leading to abnormally enlarged vessels in the intraosseus portion of the membranous bone. Immunohistochemical staining revealed positive CD31 and smooth muscle actin staining but negative proliferation and maturity markers such as Ki-67, desmin, h-caldesmon, and myofibroblast-like desmin. The follow-up of 3 of 5 patients ended up with mortality (60%). vascular malformation osseous is intraosseous vascular malformation with aggressive biological behavior associated with ELMO-2 gene mutation. Further studies for obtaining prenatal diagnosis and achievement of gene therapy should take place. As the disease rapidly progresses as the affected individual grows, surgical interventions should be taken into consideration before the initiation of complications.

Generalised fibrotic gingival enlargement in a psoriatic patient: an association or a coincidence?

Gingival fibromatosis is a rare, benign, slow progressive fibrous overgrowth of gingiva, with great genetic and clinical heterogeneity. It can be inherited as an isolated trait (hereditary/idiopathic gingival fibromatosis), and/or as a component of a syndrome. We report a case of a young girl suffering from psoriasis who also presented with an unusual generalised idiopathic gingival fibromatosis. Psoriasis, a chronic inflammatory skin disease, of multifactorial origin, is characterised by keratinocyte hyperproliferation, dedifferentiation, neoangiogenesis and inflammation. T cell-mediated immunity is considered to be the key element in the disease process. The existence of oral mucosal alterations in patients with psoriasis is a controversial topic, as histopathological correlations are not clearly evident, and oral and cutaneous lesions do not follow a parallel course. However, this article highlights a possible association of T-lymphocyte stimulation inducing fibroblasts to undergo epidermal hyperproliferation and increased collagen production in the gingiva, which in turn may be responsible for inducing gingival hyperplasia.

The autosomal recessive inheritance of hereditary gingival fibromatosis

Hereditary gingival fibromatosis (HGF) is a rare condition which is marked by enlargement of gingival tissue that covers teeth to various extents leading to aesthetic disfigurement. This study presents a case of a 28-year-old female patient and 18-year-old male who belong to the same family suffering from HGF with chief complaint of overgrowing swelling gingiva. The presence of enlarged gingiva with the same eruption was found in their other family members with no concomitant drug or medical history, and the occurrence of HGF has been found in one generation of this family which may indicate the autosomal recessive inheritance pattern of HGF. Hereditary gingival fibromatosis is an idiopathic condition as its etiology is unknown and it was found to recur in some cases even after surgical treatment. Both patients underwent thorough oral prophylaxis and later surgical therapy to correct the deformity.