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, cau sing aesthetic and functional problems. Both genetic and pharmacologic ally induced forms of gingival fibromatosis are known. The most common genetic form, hereditary gingival fibromatosis (HGF), is usually tran smitted as an autosomal dominant trait, although sporadic cases are co mmon and autosomal recessive inheritance has been reported. The geneti c basis of gingival fibromatosis is unknown. We identified an extended family (n = 32) segregating an autosomal dominant form of isolated gi ngival fibromatosis. Using a genomewide search strategy, we identified genetic linkage (Z(max) = 5.05, 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 fo r isolated HGF, and the findings have implications for identification of the underlying genetic basis of gingival fibromatosis.