Hunterian Lecture. What can we learn about mechanisms of mutation from a study of craniosynostosis?

Mutation may be defined simply as structural change affecting the genetic material. The generation of genetic variety by spontaneous mutational events has been the driving force behind evolution--without such mutation our complex human genome could not have evolved. However, as doctors, we more frequently encounter mutation in the context of human disease, whether in somatic cells as a cause of cancer, or in the germline as a cause of inheritable disease. In these contexts, the processes of mutagenesis are relevant to every field of medicine. Scientific study of mutational mechanisms has logically been founded in the relatively simple genetic systems of the prokaryotes and such lowly eukaryotes as the fruit-fly. The study of human clinical genetics approaches the problem from quite the opposite direction--from that of the most highly evolved genetic system. Whilst this approach may be dependent less on logical progression and more on phenomenology, it nevertheless provides a complementary avenue for the observation and study of mutational mechanisms. The genetic research described in this article is firmly rooted in such phenomenology, based as it is on rare craniosynostosis syndromes. Over the past decade, there has been a deluge of molecular discoveries in the field of craniosynostosis. This promises improvements in classification, prognostication, pre-natal diagnosis, and perhaps ultimately for potential avenues for cure. However, exciting as these clinical prospects are, the research presented here has a different focus: it investigates the mechanistic basis underlying the craniosynostosis mutations, in the hope that such study may lead to insights applicable generally to the field of mutagenesis.