Saliva a mirror to oral health in neurofibromatosis type-1 patients

Abstract

Background Neurofibromatosis (NF) consists of a complex group of syndromes, which occur as a result of inactivation of the various tumor suppressor genes precipitating multiple cutaneous neuromas and schwannomas in the body. Neurofibromatosis type 1 (NF1)/Von Recklinghausen disease/Watson disease affects 1 in 30,000 individuals and is caused by a mutation in the tumor suppressor gene NF1, locus 17 q11.2; this is one of the largest genes in the human genome and is inherited in an autosomal dominant pattern. Case Summary A cross-sectional study was conducted in a family suffering from NF over 3 generations, consisting of 20 members, and those meeting the diagnostic criteria for NF1 according to the National Institutes of Health (Stumpf et al., 1988) were selected. Pedigree analysis, clinical examination, Ramfjord periodontal index, and sialometry were performed for the following parameters: (1) salivary flow rate—whole unstimulated saliva was considered for salivary flow rate, which was measured by asking the patient to spit out saliva into a sterile container and the amount of saliva is quantitatively measured; (2) salivary pH—salivary pH of whole unstimulated saliva was measured by using the pH meter; (3) salivary alpha amylase activity—this was measured by using the starch–saliva–iodine test. Conclusions On clinical examination, all the members of the family showed distinctive osseous lesions at the base of the tongue. Salivary analysis revealed decreased salivary flow rate and increased pH, making the individuals prone to periodontitis caused by decreased clearance and enzymatic activity. Alterations in the salivary glands (acini and ducts) is caused by mutations in the NF1 gene. Neurofibromin is known to play important role in salivary glands cell division and differentiation via the Rho–rock–LIM kinase-2 pathway; hence the defect in neurofibromin results in defective salivary gland cell differentiation, causing nonfunctional cells and making the individual prone to hyposalivation.