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Published 5/1/2009
Michael J. Econs, MD; Craig B. Langman, MD

Seeking treatment for rare bone diseases

The first “Advances in Rare Bone Diseases” meeting, held last October at the National Institutes for Health and organized by the U.S. Bone and Joint Decade and the Rare Bone Disease Patient Network, brought together a unique group of individuals and organizations to create new opportunities, further understanding of rare bone diseases, and explore specific applications to the unique diseases and conditions represented.

Basic and translational research has progressed to partnering with industry to devise some very promising treatments for some conditions, including hypophosphatasia and X-linked hypophosphatemia. Presentations updated attendees about the current state of the science for each disease and showcased work done by some of the best young investigators in the world.

In addition, attendees found out how the Office of Rare Diseases could assist patient support groups and investigators, what the process is for designating an “orphan disease,” and why academic and industry partnerships are needed for therapeutic advances.

For example, work is currently being done to identify tissue-specific enhancers that regulate gene expression. Such work will have important implications for rare bone disorders as researchers seek to understand phenotypic variability among patients who have the same genetic basis for a disease.

The rationale and several applications for the formation and delivery of self-assembling bio-nanostructures to human disease were also presented. Such structures allow precise, often repetitive delivery of growth factors, supporting frameworks, and critical enzymes to groups of cells, a given organ, or even to the whole body through the bloodstream, to correct genetic and structural defects.

In disease-specific sessions, patients, members of the patient support groups and foundations, industry representatives, and clinical and basic researchers addressed the question “What basic and clinical research is needed to assist in the development of new therapies?” These sessions pointed out the diversity in the state of knowledge among the rare bone diseases—from well-known conditions with new therapies starting to emerge to conditions with little to no information about their pathogenesis.

In several breakout groups, participants thought that a patient registry with detailed clinical information was critical to gaining the phenotypic information required to push the field forward. Development of patient registries may be another area for collaboration between academic physician scientists and patient support groups or foundations. Care must be taken, however, to ensure that the registries are set up to maximize their usefulness to researchers.

On some level, the distinction between rare and common disease is somewhat artificial because research into rare diseases frequently benefits common diseases. For example, research on osteopetrosis has enlightened osteoclast biology and work in familial Paget’s disease.

This first meeting not only featured new science outside of traditional bone research that may be very useful, but also reinforced the mutual need for dialogue between patient groups and scientists and the importance of patient support groups in the successful development of new therapies. Future meetings will continue to provide a forum for new, creative venues for understanding mechanisms of disease and achieving novel diagnostics and therapeutics.

Michael J. Econs, MD, of the Indiana University Department of Medicine, and Craig B. Langman, MD, of Northwestern University/Children’s Memorial Hospital, cochaired the first Advances in Rare Bone Diseases conference.


  1. Sacket, DL, Rosenberg WM. The need for evidence-based medicine. J R Soc Med. 1995;88:620-4.
  2. Wright JG, Swiontkowski MF, Heckman JD. Introducing Levels of Evidence to The Journal., Ed. J Bone Joint Surg 2003; 85-A:1-2.