Lynch syndrome (LS) is the most common cause of inherited colorectal cancer, a disease with a high mortality rate. An estimated 37,000 of diagnosed colorectal cancer cases worldwide are attributed to Lynch syndrome each year. Intensive cancer screening, with early initiation and frequent follow-up, can reduce colorectal cancer incidence and mortality in LS patients. This book provides an up-to-date overview on the genetic and epigenetic basis of Lynch syndrome. It evaluates clinical features of the disease and critically comments on molecular tools available for identifying mutations responsible for Lynch syndrome; in addition the importance of functional assays that can help clarify the clinical nature of identified mutations is also discussed. The book also focuses on challenges in genetic counselling of at-risk individuals and discusses related ethical issues. The purpose of the book is to give a concise knowledge base for the broader scientific and medical community, including genetic counselors, in order to improve awareness on the potential impact that the diagnosis of LS has on treatment, management and surveillance of LS patients.