The 2nd Edition of Metabolic Diseases provides readers with a completely updated description of the Foundations of Clinical Management, Genetics, and Pathology. A distinguished group of 31 expert authors has contributed 25 chapters as a tribute to Enid Gilbert-Barness and the late Lewis Barness--- both pioneers in this topic. Enid’s unique perspectives on the pathology of genetic disorders and Lew’s unsurpassed knowledge of metabolism integrated with nutrition have inspired the contributors to write interdisciplinary descriptions of generally rare, and always challenging, hereditary metabolic disorders. Discussions of these interesting genetic disorders are organized in the perspective of molecular abnormalities leading to morphologic disturbances with distinct pathology and clinical manifestations. The book emphasizes recent advances such as development of improved diagnostic methods and discovery of new, more effective therapies for many of the diseases. It includes optimal strategies for diagnosis and information on access to specialized laboratories for specific testing. The target audience is a wide variety of clinicians, including pediatricians, neonatologists, obstetricians, maternal-fetal specialists, internists, pathologists, geneticists, and laboratorians engaged in prenatal and/or neonatal screening. In addition, all scientists and health science professionals interested in metabolic diseases will find the comprehensive, integrated chapters informative on the latest discoveries. It is our hope that the 2nd Edition will open new avenues and vistas for our readers and that they will share with us the interest, excitement and passion of the research into all these challenging disorders.