Meet the Principal Investigators


Rabi Tawil, MD. Professor of Neurology
Director of the Fields Center

Dr. Tawil is a clinician-researcher with long standing involvement in FSHD (FSHD dystrophy) research. His FSHD research has included an extensive natural history study, studies correlating the genetic defect and the clinical severity, and the first controlled therapeutic trials in this condition. More recently, his expression study, done in collaboration with Dr. Thornton, raised the possibility of vascular abnormalities in FSHD muscle. He has organized and chaired several international FSHD meetings and has served on the FSH Society scientific advisory board for ten years. He is also a Co-Investigator for the National Registry of Myotonic Dystrophy and FSHD Patients and Family Members, instituted to link patients with investigators to facilitate research into these diseases.

You may reach Dr. Tawil at:

Charles Thornton, MD. Professor of Neurology
Co-Principal Investigator of the Fields Center

The Fields Center is fortunate to have the support of Dr. Thornton, a respected scientist whose research was instrumental in the discovery of the cellular and molecular pathophysiology of myotonic dystrophy. He has collaborated with Dr. Tawil for over five years, providing microarray analyses and control group samples for molecular biology experiments. Dr. Thornton is also a Co-PI for the National Registry of Myotonic Dystrophy and FSHD Patients and Family Members, and is a highly sought after speaker and educator. In addition to maintaining a clinical practice, he conducts rigorous bench research as well as clinical trials.

Dr. Thornton can be reached at:


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Silvere van der Maarel, PhD. Professor of Medical Genetics
Co-Director of the Fields Center

Dr. van der Maarel is the world’s leading authority on the genomic aspects of FSHD. His lab was instrumental in the discovery of the FSHD genetic defect in 1992. Under his leadership, the Leiden laboratory has made several important observations including the discovery of the A and B variants on 4q35 which has important implications both for the accuracy of genetic testing as well as the underlying molecular mechanism. His team has also confirmed the occurrence of large proximal deletions in FSHD, and the occurrence of FSHD in patients without D4Z4 deletions but with focal changes in DNA methylation. He has recently outlined evidence for the function of FRG1, a candidate gene in FSHD. Dr. van der Maarel and his team will provide state of the art molecular analyses of subject DNA samples to better characterize patients with the disease as well as to look at changes at the RNA and protein levels in both biopsy and immature muscle cell cultures. Dr. van der Maarel has also organized and chaired numerous international symposia on FSHD and has worked in with lay organizations in the United states and The Netherlands.

You can reach Dr. van der Maarel at:


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Stephen Tapscott, MD, PhD, Research Scientist                                                                                                                     Consultant to the Fields Center

Dr. Stephen Tapscott has a long standing research interest in the molecular processes responsible for skeletal muscle development and the influence of muscle regulatory genes on expression through chromatin remodeling.  His research interests extend to genetically determined diseases of muscle including the molecular mechanisms underlying myotonic muscular dystrophy and the development of stem cell and gene-based, therapeutic approaches to Duchenne dystrophy. Dr. Tapscott has collaborated with the Fields Center investigators on FSHD for a number of years. His expertise, as well as that of his collaborators at the Hutchinson Cancer Research center in epigenetics, will be crucial in helping unravel the disease mechanism in FSHD.

You can reach Dr. Tapscott at