It has been over 30 years since the publication of the first edition of this book in 1975. Over the years there has been amazing progress in the fields of medical imaging, syndromology, metabolic disorders, and skeletal dysplasias. Even more recently the explosion in the field of molecular biology and gene identification has made the subjects covered in this edition even more exciting. I have tried to incorporate as much of this into the text as possible. The first edition of the book covered about 540 entities. In the second edition, about 700 subjects were discussed. By the third edition nearly 1000 syndromes, metabolic disorders, and skeletal dysplasias were included. The fourth edition contained over 1000 fully described entities as well as 1250 entries in abbreviated form included in a gamuts section. The gamuts references numbered about 1800. The third and fourth editions were divided into three separate chapters (Syndromes, Metabolic Disorders, and Skeletal Dysplasias). For the reader’s convenience, I have chosen to abridge this edition into two main sections with both syndromes and metabolic disorders alphabetically in one section and the skeletal dysplasias in a separate section.
I hope this will make usage of the text easier. This fifth edition contains 120 new fully described entries, including both entities and tables. There are about 90 new syndromes and metabolic disorders and 35 new skeletal dysplasias. To make the text more user-friendly for the geneticist as well as the radiologist and clinician, I have included the OMIM number for appropriate entries. The gamuts section has also been significantly improved and expanded with the addition of a searching CD included with this edition to allow searches using several symptoms or signs to narrow the search to a smaller number of entities, whether they are common, uncommon, or rare. The gamuts section has been increased so that there are over 22,500 entries and over 4500 gamuts-related references. The fifth edition also contains some new tables, including the overall radiographic expression of the entire group of mucopolysaccharidoses/mucolipidoses (dysostosis multiplex) and the general radiographic expression of chromosome abnormalities. A number of new tables regarding groups of important mutational disorders are also found. In this edition the articles are cited not only by the author’s name, but also the publication year, which will make it easier to find specific references. Appendix A contains the most recent Nosology and Classification of Genetic Disorders of Bone (Skeletal Dysplasias). In Appendix B, I have included a chapter on the radiographic approach to the skeletal dysplasias, which should be valuable to the novice as well as to those taking board examinations. I hope that these changes will make the text more userfriendly for all of us.