Lactose intolerance: diagnosis, genetic, and clinical factors

Rejane Mattar, Daniel Ferraz de Campos Mazo, Flair José CarrilhoDepartment of Gastroenterology, University of S o Paulo School of Medicine, S o Paulo, BrazilAbstract: Most people are born with the ability to digest lactose, the major carbohydrate in milk and the main source of nutrition until weaning. Approximately 75% of the world's population loses this ability at some point, while others can digest lactose into adulthood. This review discusses the lactase-persistence alleles that have arisen in different populations around the world, diagnosis of lactose intolerance, and its symptomatology and management.Keywords: hypolactasia, lactase persistence, lactase non-persistence, lactose, LCT gene, MCM6 gene