In this book, internationally recognized experts review the most important advances regarding the group of human developmental disorders caused by constitutive dysregulation of the Ras-MAPK signalling pathway, including Noonan, cardiofaciocutaneous, LEOPARD and Costello syndromes. A historical overview given by Jacqueline Noonan is followed by chapters dedicated to comprehensive clinical summaries of each condition and up-to-date reviews on associated gene mutations and molecular pathomechanisms. Genotypephenotype correlations are outlined. Further topics include the characterization and underlying mechanisms of common abnormalities in these syndromes such as growth failure, heart defects, and tumor risk. Animal models and the relation to neurofibromatosis type 1 are discussed. The final chapter covers the critical area of treatment including prospects emerging from an improved understanding of the pathophysiology of these disorders. Providing a concise overview of a very rapidly developing field and suggesting ways how to integrate the latest findings from basic molecular research into clinical practice, this book will be of interest to clinical geneticists, pediatricians, pediatric cardiologists, and pediatric endocrinologists, as well as to human molecular geneticists and other basic researchers working on the RAS pathway.