This henceforth classical textbook has become indispensable for those in the front line dealing with metabolic disorders. As with previous editions the book is aimed at all those involved with this specialty including pediatricians, biochemists, dieticians, neurologists, internists, geneticists, psychologists, nurses, and social workers. This 4th edition has been thoroughly updated and revised and John Walter has joined the three other editors. One new chapter on Neonatal screening by tandem MS/MS has been added and several new groups of disorders have been included; for example defects involving the pentose phosphate pathway (polyols metabolism) and disorders of glucose transport. The first chapter presents the clinical approach to inherited metabolic disease using many algorithms and tables and has been entirely revised and extended to include adult metabolic medicine. It now incorporates many new findings particularly in neuroradiology and neurophysiology and emphasises those disorders for which treatment is available. This accessible and practical book can be used either by going directly to the relevant chapter when the diagnosis is already suspected or by referring to Chapter 1 if it is unknown. Despite the numerous updates the book has been maintained at a reasonable size and is published as a single volume of approximately 550 pages divided into 43 Chapters.