Variations in centromeric heterochromatin among patients with pre‐malignant and malignant oral diseases

Polymorphism of heterochromatic regions of chromosomes 1, 9 and 16 was studied in 60 oral cancer patients, in 40 patients with oral submucous fibrosis (OSMF) and in 60 normal healthy subjects. The size heteromorphism was significantly greater (p < 0.001) in chromosome 1 of the patients. Localization variants were also significantly more frequent among the patients (p < 0.05 for OSMF and < 0.001 for oral cancer patients). The C‐band heteromorphism patterns remained comparable in OSMF and in oral cancer patients, with chromosome 1 being the most frequently involved. On correlating the tobacco/areca‐nut chewing habit with the presence of C‐band heteromorphism, we observed that C‐band heteromorphism was present in 89% of the habit‐free oral cancer patients and 80% of the OSMF patients with relatively shorter exposure to this habit, i.e. < 5 years. This signifies that genetic factors are important in the causation of oral precancerous and cancerous conditions and that polymorphism of the heterochromatic regions does appear to play a role in these conditions.