Since the publication of the first edition sixteen years ago, Inborn Metabolic Diseases – Diagnosis and Treatment has become a classic textbook, indispensable for those involved in the care of children and adults with inborn errors of metabolism, including pediatricians, biochemists, dieticians, neurologists, internists, geneticists, psychologists, nurses, and social workers. This new 4th edition has been extensively revised. An additional clinician, John Walter, has joined the three other editors, there is a new chapter on neonatal screening, including tandem MS/MS, and several new disorders have been included, for example defects involving the pentose phosphate pathway (polyol metabolism) and disorders of glucose transport. However, the focus of the.