This clinically organized, user-friendly, handbook is intended to help general physicians and medical specialists in training with the first critical steps in clinical diagnosis: how to determine that this is an inherited metabolic disease, and where to go from here to establish a diagnosis. It is a well-illustrated text that is organized around the clinical presentation of the disease. Biochemical and metabolic concepts are presented in a clinically relevant context. It functions to complement more traditional textbooks which are organized biochemically. The book serves as an entrance to the discipline, to help non-expert physicians and advanced medical trainees to overcome the intimidation they are accustomed to experiencing when dealing with metabolic problems. This new edition has been expanded to include substantially more on mitochondrial diseases, new imaging techniques, and new techniques for screening and diagnosis.