The objective of this proposal is to better understand the pathogenesis of head and neck squamous cell carcinomas (HNSCCs) for individuals with FA, in order to find practical and proactive preventive strategies to improve their quality of life. Specifically, this research aims to investigate the role of acetaldehyde (a reactive compound found in our environment, tobacco smoke, foods, beverages, formed upon alcohol consumption and as a result of the microbiome metabolism) in the increased incidence of oral cancer in FA patients. The goal of this work is to measure the overall exposure to acetaldehyde resulting from food and a low dose of alcohol and measure the corresponding acetaldehyde-derived DNA damage in the oral cavity of FA patients, while setting the stage to investigate the role of the oral microbiome in influencing this exposure.