Dr Oliver Quarrell is a Consultant Clinical Geneticist at Sheffield Children's Hospital. He started work on his MD in HD just after the gene was localised to chromosome 4. He has worked on aspects of HD ever since and is author of Huntington's Disease: The Facts. He remains actively involved with the Huntington's Disease Association in the UK, and from there has had the opportunity to expand the JHD project. He is the lead facilitator of the JHD working group of the European Huntington's Disease Network (EHDN).
Helen Brewer works as the Care Adviser for JHD with the Huntington's Disease Association in England and Wales (HDA), offering advice and support to families affected by JHD and professionals involved in their care. She is currently coordinating the work of the JHD working group of EHDN.
Professor Ferdinando Squitieri is a Neurologist with PhD in neurobiology, and with expertise in molecular genetics and psychiatry. He has led the Neurogenetics Unit at Neurological Institute Neuromed in Pozzilli (Italy), since 1998. He has expertise in HD, having published many manuscripts on clinical and genetic aspects of this pathology. He coordinates the predictive testing program at Neuromed and is a scientific coordinator of the Family HD Association AICH-Neuromed in Italy. Dr Roger A. Barker is a Reader in Clinical Neuroscience and Honorary Consultant in Neurology at Addenbrooke's Hospital, Cambridge (UK). His main interests are in the neurodegenerative disorders of the nervous system, in particular Parkinson's disease and Huntington's disease. He combines basic research looking at cell therapies to treat these conditions with clinically based work on defining the natural history and heterogeneity of both Huntington's disease and Parkinson's disease. He is a member of the PDS Research Advisory Panel, the MRC Stem cell Liaison Committee and is co-editor in chief of the journal Advances in Clinical Neuroscience and Rehabilitation.

Dr. Martha A. Nance is Adjunct Associate Professor in the Department of Neurology at the University of Minnesota (USA). She received her B.S. from Yale University, her MD from Medical College of Virginia, and completed her neurology and genetics training at the University of Minnesota, where she is now an Adjunct Professor. She has been the Medical Director of the Hennepin County (Minnesota) Medical Center HD Center of Excellence since 1991 and is a member of the Huntington Study Group. She is the author of The Physician's Guide to HD and The Juvenile HD Handbook, both published by the Huntington Disease Society of America.
Professor Bernhard Landwehrmeyer is Professor of Neurology at the University of Ulm, Germany. He trained as a doctor in Freiburg, Germany, qualifying in 1988, and became full Professor of Neurology at the University of Ulm in 2000. Since 2003 he has been the Chief Executive of the European Huntington's Disease Network (EHDN) and he has overseen the establishment of the network.