Approaches for skeletal gene therapy

The role of gene therapy in the treatment of musculoskeletal disorders continues to be an active area of research. As the etiology of many musculoskeletal diseases becomes increasingly understood, advances in cellular and gene therapy may be applied to their potential treatment. This review focuses on current investigational strategies to treat osteogenesis imperfecta (OI). OI is a varied group of genetic disorders that result in the diminished integrity of connective tissues as a result of alterations in the genes that encode for either the proα1 or proα2 component of type I collagen. Because most forms of OI result from dominant negative mutations, isolated gene replacement therapy is not a logical treatment option. The combined use of genetic manipulation and cellular transplantation, however, may provide a means to overcome this obstacle. This article describes the recent laboratory and clinical advances in cell therapy, highlights potential techniques being investigated to suppress the expression of the mutant allele with antisense gene therapy, and attempts to deliver collagen genes to bone cells. The challenges that the investigators face in their quest for the skeletal gene therapy are also discussed.