NIAMS Funds Multiple Research Grants in Osteogenesis Imperfecta

Research on osteogenesis imperfecta (OI), a genetic disorder characterized by bones that break easily, has received a boost from the award of five new grants by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) at the National Institutes of Health. The grants, which total $1.6 million, support research activities ranging from cutting-edge gene and cell therapies to testing drug treatments in mouse models.

"These projects seize new research opportunities for rare genetic disorders like osteogenesis imperfecta," said NIAMS Director Stephen I. Katz, M.D., Ph.D. "We are excited about their potential for improved diagnosis and treatment, and encouraged by the hope they bring to people with osteogenesis imperfecta and their families."

The new NIAMS-funded studies include:

Development of a Treatment for Osteogenesis Imperfecta, Bruce R. Martin, Ph.D., University of California, Davis. Using a mouse model for OI, researchers will test the effectiveness and mechanisms of pamidronate, a bisphosphonate drug used to increase bone mineral density and decrease bone loss. Because pamidronate could interfere with bone growth, researchers will also determine whether it will have a negative effect on the growth of children with OI.

Alendronate Use in Models of Osteogenesis Imperfecta, Cathleen L. Raggio, M.D., Hospital for Special Surgery, New York, N.Y. This study will test the new osteoporosis drug alendronate in mouse models of mild-to-moderate OI. Alendronate is a bisphosphonate used to increase bone mineral density and decrease bone loss. Researchers will compare bone quality before and after treatment, focusing on the number of fractures, bone and tooth density and geometry, bone structure and biological composition, as well as mechanical movement. Study results may help determine treatment of infants and children with different types of OI.

Evaluation of Cellular Gene Therapy for Osteogenesis Imperfecta in an Animal, Christopher Niyibizi, Ph.D., University of Pittsburgh. This study will use mouse models to test gene and cell therapy methods for correcting the gene mutations that cause some forms of OI and other bone-related diseases. In future studies, researchers will (1) determine the amount of collagen made by the transplanted gene cells in the bones of recipient mice and (2) assess the bone quality based on radiographic images, laboratory tests and biomechanical analysis.

Mutational Effects on Collagen's Structure and Stability, Teri E. Klein, Ph.D., Stanford University, California. This study concentrates on the structure and function of collagen in its normal and altered states. Researchers hope that gaining a better understanding of the changes that occur from gene mutations in collagen will lead to development of mechanisms that will improve the diagnosis and treatment of collagenous genetic disorders such as OI.

Expansion of Stem Cells for Skeletal Tissues, Darwin J. Prockop, M.D., Tulane University Medical Center, New Orleans. Stem cell therapy holds great promise for genetic disorders such as OI. However, questions remain about generating new cells with normal structure and function, as well as regulating cell replication. This study will look at whether replicated cells maintain properties of original cells and whether they form the desired cells: osteoblasts, chondrocytes and adipocytes. Researchers also will determine how to regulate the number of stem cells produced in culture.

Funding for these projects comes on the heels of the meeting "New Research Strategies in OI," held in September 1999. This meeting was co-sponsored by the NIAMS, the NIH Office of Rare Diseases, the Osteogenesis Imperfecta Foundation and the Children's Brittle Bone Foundation. Experts in OI and other bone disorders were brought together to identify ways to expand the scope of research on OI. A summary of the meeting is located at www.nih.gov/niams/reports/osteogenimperf.htm.

Osteogenesis Imperfecta (OI) is a genetic disorder affecting 20,000 to 50,000 adults, children and infants in the United States. Bones break easily, often from little or no apparent cause. There are at least four types of OI, representing extreme variation in severity from one person to another. For example, a person may have just a few or as many as several hundred fractures in a lifetime.

OI is caused by a genetic defect that affects the body's production of collagen, the major protein of connective tissue, cartilage and bone. In OI, a person has either less collagen than normal, or a poorer quality of collagen than normal, leading to weak bones that fracture easily.

There is no cure for OI. Current treatment is directed toward preventing or controlling the symptoms, maximizing independent mobility and developing optimal bone mass and muscle strength.

The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) is a component of the National Institutes of Health. The mission of the NIAMS is to support research into the causes, treatment and prevention of arthritis and musculoskeletal and skin diseases, the training of basic and clinical scientists to carry out this research, and the dissemination of information on research progress in these diseases. For more information about NIAMS, call our information clearinghouse at (301) 495-4484 or (877) 22-NIAMS (free call) or visit the NIAMS web site at http://www.nih.gov/niams.

For more information on osteogenesis imperfecta, contact the following organizations:

National Institutes of Health Osteoporosis and Related Bone Diseases~ National Resource Center 1232 22nd St., NW Washington, DC 20037-1292 Phone: (800) 624-BONE TTY: (202) 466-4315 Fax: (202) 293-2356 Web site: www.osteo.org

Osteogenesis Imperfecta Foundation 804 W. Diamond Avenue, Suite 210 Gaithersburg, MD 20878 Phone: (301) 947-0083 Fax: (301) 947-0456 Web site: http://www.oif.org/

Children's Brittle Bone Foundation 7701 95th Street Pleasant Prairie, WI 53158 Phone: (847) 433-4981 Fax: (262) 947-0724 Web site: www.cbbf.org