Hereditary fibrous hyperplasia of the gingiva with varying penetrance and expressivity

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.

Hereditary gingival fibromatosis: clinical and ultrastructural features of a new family

Objective: This article describes the diagnosis, clinical and microscopic (histopathology and ultrastructural) features and treatment of a new family with hereditary gingival fibromatosis (HGF) and highlights the importance of this genetic condition. Study Design: To characterize the pattern of inheritance and the clinical features, members of a new family with HGF were examined. The pedigree was reliably constructed including the four latest generations of family. Hematoxylin and eosin staining and ultrastructural analysis were performed with the gingival tissue. Results: Examination of the family pedigree revealed that the patient III-2 represent the index patient of this family (initial patient with a mutation), which was transmitted to her daughter through an autosomal dominant mode of inheritance. The affected patients showed a generalized gingival overgrowth. The patient was treated with surgical procedures of gingivectomy and gingivoplasty. The diagnosis was confirmed by histopathology examination that showed a well-structured epithelium with elongated and thin papillae inserted in fibrous connective tissue with increased amount of collagen. The ultrastructural aspects of the tissue show collagen fibrils exhibiting their typically repeating banding pattern with some fibrils displaying loops at their end. Moreover, it was possible to seen in some regions fibrillar component presenting tortuous aspects and loss of the alignment among them. Conclusions: This HGF frequently resulted in both esthetic and functional problems. The genetic pattern of this Brazilian family suggested a new mutation, which was later transmitted by an autosomal dominant trait.

Key words:Gingival fibromatosis, genetic disease, pedigree, ultrastructure.

Idiopathic gingival enlargement associated with generalized aggressive periodontitis in a 19-year-old female

Gingival enlargement, one of the manifestations of gingival and periodontal disease, is also known as gingival overgrowth. Idiopathic gingival enlargement is a rare gingival overgrowth, which is of an undetermined cause. This unknown etiology has now been linked to specific genes and idiopathic gingival enlargement is at times referred to as hereditary gingival enlargement. This condition is a benign, slow growing proliferation of gingival tissues. Aggressive periodontitis is the rapid form of periodontal disease which is characterized by extensive periodontal tissue destruction, increased host-susceptibility toward periodontal disease progress and a genetic predilection toward disease occurrence. We present a rare case of idiopathic gingival fibromatosis associated with generalized aggressive periodontitis in a young female. The patient presented with classic clinical and radiographic presentation associated with gingival enlargement and aggressive periodontitis. The diagnosis was then confirmed by histopathological and neutrophil functions tests.

Hereditary gingival fibromatosis

Hereditary gingival fibromatosis (HGF) is a rare condition that can occur as an isolated disease, chromosomal abnormality, or as part of a number of syndromes. The gingival enlargement in HGF can be so severe that it can cover the crowns of teeth completely, causing severe functional derangement and facial disfigurement. Through review of literature revealed that HGF is usually an autosomal dominant condition, however the recessive forms are also reported. The hyperplastic gingiva is firm on palpation and has normal color with abundant stippling on the adjacent gingiva. The buccal and lingual gingiva may be involved in both the mandible and maxilla. The degrees of gingival enlargement show both intra- and interindividual variations. Here, an interesting case report of massive HGF has been presented.

Severe gingival enlargement associated with aggressive periodontitis

Enlargement of the gingiva can be due to various causes. Most prevalent are the inflammatory type and drug-induced type of gingival hyperplasia. However, sever enlargement associated with an aggressive type of periodontitis is an infrequent finding. Reported here is a case of a female patient aged 18 years who presented with severe enlargement of the maxillary and mandibular gingiva. Examination revealed enlargement extending up to the incisal edge of all the teeth and also an associated generalized loss of attachment with radiographic evidence of reduced bone height resembling an aggressive type of periodontitis. There were no associated systemic signs and symptoms or any family history except that there was generalized vitiligo of the skin and oral mucous membrane. The case was treated by gross electrosection of the gingiva.

Hereditary gingival fibromatosis: characteristics and novel putative pathogenic mechanisms

Hereditary gingival fibromatosis (HGF) is a rare condition that can occur as an isolated disease or as part of a syndrome or chromosomal abnormality. In severe cases, the gingival enlargement may cover the crowns of teeth and cause severe functional and esthetic concerns. Histological and cell culture studies have uncovered some of the molecular and cellular changes associated with HGF. However, the pathogenesis of the disease is still largely unknown. Recent studies about the genetic characteristics of HGF have provided novel clues about the potential pathogenic mechanisms. In particular, mutation in the son-of-sevenless (SOS-1) gene has been associated with one form of the disease. However, HGF displays genetic heterogeneity, and mutations in other genes are also likely involved. This review outlines the current knowledge about the histological, cellular, and genetic characteristics of HGF. In addition, the potential role of the SOS-1 molecule and related novel intracellular signaling pathways in the pathogenesis of HGF will be discussed.

Characterization of fibroblasts with Son of Sevenless-1 mutation

Although non-syndromic hereditary gingival fibromatosis (HGF) is genetically heterogeneous, etiologic mutations have been identified only in the Son of Sevenless-1 gene (SOS1). To test evidence of increased cell proliferation, we studied histological, morphological, and proliferation characteristics in monolayer and three-dimensional cultures of fibroblasts with the SOS1 g.126,142-126,143insC mutation. Histological assessment of HGF gingiva indicated increased numbers of fibroblasts (30%) and increased collagen (10%). Cell proliferation studies demonstrated increased growth rates and 5-bromo-2-deoxyuridine incorporation for HGF fibroblasts. Flow cytometry showed greater proportions of HGF fibroblasts in the G2/M phase. Attachment of HGF fibroblasts to different extracellular matrix surfaces demonstrated increased formation of protrusions with lamellipodia. HGF fibroblasts in three-dimensional culture showed greater cell proliferation, higher cell density, and alteration of surrounding collagen matrix. These findings revealed that increased fibroblast numbers and collagen matrix changes are associated with mutation of the SOS1 gene in vitro and in vivo.

A novel locus for maternally inherited human gingival fibromatosis at chromosome 11p15

Human isolated gingival fibromatosis is an oral disorder characterized by a slowly progressive benign enlargement of gingival tissues. The most common genetic form, hereditary gingival fibromatosis (HGF), is usually transmitted as an autosomal dominant trait. We report here for the first time a newly identified maternally inherited gingival fibromatosis in two unrelated Chinese families and mapped this disease locus to human chromosome 11p15 with a maximum two point LOD score of 8.70 at D11S4046 (theta = 0) for family 1 and of 6.02 at D11S1318 for family 2. Haplotype analysis placed the critical region in the interval defined by D11S1984 and D11S1338. A cluster of maternally expressed genes is within this critical region. We screened individuals in these two families for mutations for all known maternally expressed genes within this region. None was found either within the coding sequence or at the intron-exon boundary of these genes. Neither did we detect any loss of imprinting in three informative imprinted genes including H19, KCNQ1 downstream neighbor (KCNQ1DN) and cyclin-dependent kinase inhibitor 1C (CDKN1C). However, gene expression profile analysis revealed reduced expression of hemoglobin beta (HBB), hemoglobin delta (HBD), hemoglobin gamma A (HBG1) and hemoglobin gamma G (HBG2) genes at disease locus in HGF patients. This study suggests that genome imprinting might affect the development of HGF.

A mutation in the SOS1 gene causes hereditary gingival fibromatosis type 1

Hereditary gingival fibromatosis (HGF) is a rare, autosomal dominant form of gingival overgrowth. Affected individuals have a benign, slowly progressive, nonhemorrhagic, fibrous enlargement of the oral masticatory mucosa. Genetic loci for autosomal dominant forms of HGF have been localized to chromosome 2p21-p22 (HGF1) and chromosome 5q13-q22 (HGF2). To identify the gene responsible for HGF1, we extended genetic linkage studies to refine the chromosome 2p21-p22 candidate interval to approximately 2.3 Mb. Development of an integrated physical and genetic map of the interval identified 16 genes. Sequencing of these genes, in affected and unaffected HGF1 family members, identified a mutation in the Son of sevenless-1 (SOS1) gene in affected individuals. In this report, we describe the genomic structure of the SOS1 gene and present evidence that insertion of a cytosine between nucleotides 126,142 and 126,143 in codon 1083 of the SOS1 gene is responsible for HGF1. This insertion mutation, which segregates in a dominant manner over four generations, introduces a frameshift and creates a premature stop codon, abolishing four functionally important proline-rich SH3 binding domains normally present in the carboxyl-terminal region of the SOS1 protein. The resultant protein chimera contains the wild-type SOS1 protein for the N-terminal amino acids 1-1083 fused to a novel 22-amino acid carboxyl terminus. Similar SOS1 deletion constructs are functional in animal models, and a transgenic mouse construct with a comparable SOS1 chimera produces a phenotype with skin hypertrophy. Clarification of the functional role of this SOS1 mutant has implications for understanding other forms of gingival fibromatosis and corrective gingival-tissue management.

Genetic linkage of hereditary gingival fibromatosis to chromosome 2p21

Gingival fibromatosis is characterized by a slowly progressive benign enlargement of the oral gingival tissues. The condition results in the teeth being partially or totally engulfed by keratinized gingiva, causing aesthetic and functional problems. Both genetic and pharmacologically induced forms of gingival fibromatosis are known. The most common genetic form, hereditary gingival fibromatosis (HGF), is usually transmitted as an autosomal dominant trait, although sporadic cases are common and autosomal recessive inheritance has been reported. The genetic basis of gingival fibromatosis is unknown. We identified an extended family (n=32) segregating an autosomal dominant form of isolated gingival fibromatosis. Using a genomewide search strategy, we identified genetic linkage (Zmax=5.05, straight theta=.00) for the HGF phenotype to polymorphic markers in the genetic region of chromosome 2p21 bounded by the loci D2S1788 and D2S441. This is the first report of linkage for isolated HGF, and the findings have implications for identification of the underlying genetic basis of gingival fibromatosis.