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. 1. Introduction Hereditary gingival fibromatosis (HGF) is a clinical condition defined as an overgrowth of gingiva [1]. This is an important and very rare dental case (1 in 750,000) which is also referred to as idiopathic gingival hyperplasia in medical history [1, 2]. The maxillary and mandibular tissues of both arches are affected by slow enlargement of gingiva. This is considered as a benign condition, that is, associated with various factors like inflammation, hormonal imbalance, neoplasia, and some unknown causes [3, 4]. Healthy gingival tissue is characterized as pink, firm, fleshy, and made up of connective tissue covered by mucous membrane surrounding the neck of the teeth in a collar-like fashion on the jaw. However the HGF present in most of the anatomic crown of teeth causes abnormally shaped teeth, abnormal tooth movement, speech disorders, and other dental and oral problems [5]. It has been reported that both males and females are equally affected, with the phenotype and genotype frequency of HGF being 1？:？175,000 and 1？:？350,000, respectively [4]. HGF is more commonly associated with an autosomal dominant gene [5, 6]. According to various studies the pedigree analyses of HGF families confirm the autosomal dominant inheritance of HGF trait, although autosomal recessive or even as X-linked inherited cases have also been reported in some literature [7, 8]. Mutation in SOS-1 or son-of-sevenless gene is responsible for this disease; this has been reported by several authors [5, 9–11]. It is a guanine nucleotide-exchange factor that functions in the transduction of signals that control cell growth and differentiation [11]. Chromosomes numbers 2, 4,