BackgroundTooth agenesis refers to the absence of one or more of the deciduous or permanent teeth. Tooth agenesis results from a series of disrupted reciprocal ectodermal mesenchymal interactions taking place during the early stages of tooth development.MethodsA narrative literature review was performed to describe the main genetic syndromes associated with tooth agenesis.Results and conclusionsThe etiology of congenital tooth agenesis is multifactorial and include genetic, epigenetic, and environmental influences. Syndromes associated with chromosomal alterations, ectodermal dysplasia, Axenfeld-Rieger syndrome, oral-facial cleft syndromes, and syndromes with cancer predisposition are among the main entities presenting with tooth agenesis.Clinical relevanceTooth agenesis disorders can affect the masticatory function and cause disfigurement leading to physiological and psychological complications. Early recognition of these entities is crucial to guide the management of the patient and to provide families with the appropriate genetic counseling.