Treatment of poor linear growth in a patient with osteogenesis imperfecta type III.

INTRODUCTION

Osteogenesis imperfecta (OI) is a group of bone and connective tissue disorders arising from a genetic defect.

CASE SUMMARY: An 11-year-old boy with OI had >50 fractures before initiating treatment with bisphosphonate (BPT) in 1999; many of these fractures required surgery. Despite improvement in bone mineral density (from 0.260 g/cm(2) in 1999 to 0.547 g/cm(2) in 2002), linear growth did not improve with BPT. Somatropin depot (SD) therapy was started in May 2002 to improve the child's poor linear growth (PLG). The rate of growth was 0.011 cm/d before SD initiation and 0.015 cm/d during SD therapy, a 36% increase in growth rate (standard physiologic rate, 0.014 cm/d). The number of fractures did not increase with the addition of SD. Insulin-like growth factor 1 levels, as well as renal and hematologic parameters indicative of safety, did not change.

DISCUSSION: Growth hormone use in mild to moderate OI has produced promising results, as in the present study. However, its long-term effectiveness and its potential for helping patients attain adequate adult stature have been questioned.

CONCLUSIONS

Short-term use of SD in the treatment of this case of PLG appeared to be effective and well tolerated. Future work is necessary to determine the long-term safety profile and effectiveness of SD therapy in children with PLG who have OI.