ABSTRACT
As medical genetics has grown, with increasing applications to different areas of medicine, so it has also differentiated. The degree of involvement of medical geneticists in different fields and the nature of the links with the various specialties involved have varied considerably, though none of the different areas have become completely separate from medical genetics as a whole. The longest established subspecialty has been clinical dysmorphology, the study of congenital malformations, largely developed in Britain by medical geneticists rather than by general paediatricians. Its combination of clinical pattern recognition, creation and use of clinical databases and links with work on developmental defects in experimental species have made it a valuable area of basic research as well as of clinical diagnosis, especially with increasing recognition of the underlying molecular and genomic defects. Clinical cancer genetics has likewise become an important field, now closely linked with cancer diagnosis and basic cancer research, largely through the recognition of single gene subsets of common cancers.
