Background & Objectives: Tumorigenesis is a multistage process in which multiple genetic abnormalities lead to malignancy. In individuals with precancerous oral lesions, allelic loss at 3p and 9p appears important in predicting who will advance to invasive oral cancer. The aim of the present study is to detect the presence of allelic imbalance at chromosome locus 9p21 in oral potentially malignant disorders though non-invasive screening method. Methodology:The study comprised of three - control group with no history of any habit ,moderate risk group with tobacco related habits over a duration of less than 2yrs and 15 patients were of high risk group with tobacco related habits over a duration of more than 2yrs.Genomic DNA was extracted from buccal epithelial cells. Al was assessed using 8 microsatellite markers located at chromosomes 9p21. Al analysis was done by PCR using primers with fluorochromes. Results: The analysis of all of the data indicated that allelic imbalance was present in exfoliated cells of the group who had oral lesions studied. None of the samples of control showed Al, confirming the apparent high specificity of the assay (100%). Conclusion: The present study, therefore, demonstrates that Allelic Imbalance (AI) on chromosome 9p is found in the oral potentially a malignant disorder at a relatively high frequency is probably an early event in oral carcinogenesis.

Allelic Imbalance (AI); Loss of Heterozygosity (LOH); Oral Potentially Malignant Disorders (OPMD); Oral Squamous cell carcinoma (OSCC)