“A man ought to read just as inclination leads him; for what he reads as a task will do him little good.”---Dr. Samuel Johnson
Advances and breakthroughs in genetic science are continually in the news, attracting great interest because of the potential, not only for diagnosing and eventually treating disease but also for what we learn about humankind through these advances. In addition, almost every new breakthrough raises a fresh ethical, social, and moral debate about the uses to which genetic science will be put, particularly in reproductive medicine and issues relating to identity and privacy. Increasingly, today’s medical graduates, and mature postgraduates,
must be equipped to integrate genetic knowledge and science appropriately into all areas of medicine, for the task cannot be left solely to clinical geneticists, who remain small in number; indeed, in many countries, there is either no structured training program in clinical genetics or the specialty is not recognized at all.
Since the publication of the thirteenth edition of Emery’s Elements of Medical Genetics, there has been a huge surge forward in our knowledge and understanding of the human genome as the technology of microarray comparative genomic hybridization has been extensively applied, both in research and clinical service settings. We know so much
more about the normal variability of the human genome as the extent of copy number variants (of DNA) has become clearer, though we are still trying to unravel the possible
significance of these in relation to health and disease. And as we write this there is great excitement about the next technological revolution that is underway, namely next-generation sequencing. Already there are dramatic examples of gene discovery in Mendelian conditions through analysis of the whole exome of very small numbers of patients with clear phenotypes. There is also more realistic anticipation than before that breakthroughs will be made in the treatment of genetic diseases, which will take a variety of different forms. Whilst discovery and knowledge proceed apace, however, the foundation for those who aspire to be good clinical practitioners in this field lies in a thorough grasp of the basics of medical genetics, which must include the ability to counsel patients and families with sensitivity and explain difficult concepts in simple language.
In this fourteenth edition of Emery’s Elements of Medical Genetics, we have tried to simplify some of the languages and reduce the redundant text where possible, to make way for some new, updated material. Several chapters have undergone significant revisions, and the range of illustrations has increased. We have listened to those colleagues (a small number!) who identified one or two errors in the last edition and also suggested ideas for improvement. Once again, we have sought to provide a balance between a basic, comprehensive
text and one that is as up-to-date as possible, still aiming at medical undergraduates and those across both medical and non-medical disciplines who simply want to “taste and see.” The basic layout of the book has not changed because it seems to work well, and for that, we remain in debt to our predecessors in this project, namely Alan Emery, Bob Mueller, and Ian Young.
Peter D. Turnpenny and Sian Ellard
Exeter, United Kingdom
November 2010