P. K. Thomas headed the Research Group on Neuromuscular Diseases of the World Federation of Neurology for more than a decade. He was determined to lead it into activities more productive than restricting its activity to organizing the international quadrennial congress, which has been so popular. Book publishing seemed to be an excellent opportunity. Yngve Olsson, President of the International Society of Neuropathology, and George Karpati joined him, and we now have a remarkable book. It is remarkable in many respects. The pathologic descriptions and color photographs are peerless. Color also illuminates the diagrams of genes, tables of diseases, and the text. All components of the book mirror the explosive expansion of knowledge in the past 2 decades, which is based on the advent of molecular genetics. Even the chapter titles are based on the molecular basis of each group of diseases: sarcolemmal and extracellular matrix defects; myonuclear abnormalities; myofibrillar and internal cytoskeletal proteins; ion channel defects; complex molecular defects (myotonic, facioscapulohumeral, and oculopharyngeal muscular dystrophies), and catabolic disorders (mitochondrial and proteolytic diseases). Due attention is given to disorders of neuromuscular transmission, metabolic myopathies, inflammatory myopathies, and others. The book is physically remarkable. It is literally lightweight even if the content is thorough and thoughtful. With a paper cover and 312 pages, it is convenient to hold and read. The index is comprehensive. The book is remarkable because there are 77 contributors. Dr Karpati has selected an all-star cast and the chapters are appropriately informative. Multiauthored books are sometimes criticized for uneven differences in writing styles. That has never bothered me, and this book takes advantage of the diverse skills of the numerous authorities. It is remarkable how many diseases have been discovered since the mid 1980s, when Louis Kunkel and his group mapped Duchenne dystrophy and identified dystrophin. Before the era of positional cloning, the recognition of hyperCKemia made it likely that the problem was in the muscle surface membrane. Little was known about the proteins in those membranes, and it would have taken eons to work through the thenknown proteins to find one that was abnormal. Dystrophin was recognized only after the gene had been mapped. Soon thereafter, Campbell and his team found that the lists of sarcoglycans and limb-girdle dystrophies became longer and longer. Rapidly, more gene products were identified, and some 50 muscle diseases have been newly recognized in the last decade. The descriptions of these diseases are excellent, and I intend no invidious comparisons if I single out one chapter for comment. Charles Thornton’s description of the molecular basis of myotonic dystrophy is an acme of surprise. Who would have thought that messenger RNA could be myotoxic and responsible for a disease? Many other molecular mechanisms pose problems, too, for it is not yet known how the causes of an inherited disease (mutation and abnormal gene product) set into motion the numerous steps of pathogenesis that ultimately result in the clinical disease. There is still much to be done. Karpati himself deals with the ultimate question for our patients: How do we convert the molecular abnormalities into effective treatment or, better, prevention? There are other important books on muscle disease, especially the multivolume Myology, edited by Andrew Engel and Clara Franzini-Armstrong. But this one has the advantage being sufficiently compact (just 312 pages within a paper cover) to be updated at brief intervals, and the brilliant colors put it in position to compete with online texts, at least until the price and speed of downloading in color become more congenial. I have one suggestion for the next edition; Some but not all of the authors have followed the McKusick guidelines; the eponym becomes nominative rather than possessive. It isMadisonAvenue,notMadison’sAvenue. The concern is not merely a matter of consistency, but journals are gradually adopting McKusick’s suggestions.Avoiding thepossessive prevents the error made by one British author here, who mentioned “Gower’s sign.” Poor old Gowers! The book is dedicated to Kiichi Arahata, one of the most productive of young neuromuscular investigators. I give kudos also to George Karpati, P. K. Thomas, and Yngve Olsson for their vision and execution. This book will be useful for practicing neurologists, students, graduate trainees, and investigators.