The phenotypic overlap of syndromes associated with hereditary gingival fibromatosis: follow-up of a family for five years.

Hereditary gingival fibromatosis (HGF) is characterized by the slowly progressive fibrous enlargement of gingival tissue. It usually develops as an isolated disorder but can also be one feature of various syndromes. The currently preferred terminology of these syndromes mainly describes the clinical features of the disorder without identifying the cause. In this report, we present the 5-year follow up of a family with HGF and features of 3 previously described syndromes: Jones syndrome, Zimmerman-Laband syndrome, and HGF-hypertrichosis syndrome. The 45-year-old father had HGF, hypertrichosis, hearing loss, and short stubby fingers and toes with hypoplasia of the terminal phalanges and hypoplasia of the nails on the thumbs. The features of 13-year-old son were almost identical to those of his father except for hypertrichosis, but in addition he was mentally retarded. Although the 10-day-old son had HGF and defective fingers, the mother and 7-year-old daughter were unaffected. Owing to the overlap of these syndromes, we argue that the identification of the genetic pathways and mechanisms will be the most important factor in classifying these disorders, with the phenotype playing a minor role.