ObsGEN: a digital tool to support the diagnosis of rare genetic obesity

Abstract ObsGEN is a free, web-based clinical decision support tool developed to facilitate the identification of rare genetic forms of obesity, including monogenic and syndromic etiologies. Implemented on the REDCap platform, it guides clinicians through a structured 10-15-minute questionnaire covering key phenotypic domains: age of onset, weight trajectory, hyperphagia, neurodevelopmental features, and signs of hypothalamic dysfunction. Based on the inputted data, ObsGEN provides automated, phenotype-driven diagnostic hypotheses, genetic testing recommendations, and direct access to national expert centers. The tool aims to support early recognition of rare obesity syndromes, enabling timely referral, access to targeted therapies, and personalized care strategies. Since its implementation in 2019, ObsGEN has been used by over 1150 clinicians in France, incorporated into national clinical workflows, and contributed to the development of the French National Diagnosis and Care Protocol for rare obesities. By operationalizing a precision medicine approach, ObsGEN enhances diagnostic accuracy and promotes equitable access to expert evaluation in both pediatric and adult obesity care. More info: http://obsgen.nutriomics.org