Bone Abstracts

Background: Final stature is a result of concomitant growth hormone (GH)-IGF1 axis integrity, a healthy environment and genetic background. Occasionally, growth occurs despite remarkable impairment in hormone profile. Presenting problem: An uncommon case of longitudinal growth in a boy with very low IGF1 concentrations and clinical diagnosis of osteopetrosis. Clinical management: We report on the case of a 19 year-old male patient with the diagnosis of osteopetrosis who had a falloff in growth at the age of 14 years, Tanner G1P1, but recovered height gain velocity months latter, suggesting a prepubertal slowdown in growth. However, his IGF-I concentrations were consistently low (<−2 SDS). Three GH provocative tests were performed and resulted in appropriated cortisol release, but no response of GH to the stimulus. Lumbar spine bone mass was increased (z-score=+5.1) and there were calcifications within the skull base but normal brain MRI. At age of 16 years he had a femural fracture with abnormal consolidation, leading to walking limitation. His final height is 179 cm (0.43 SDS), above familial target height.

Discussion: This case report describes a patient harboring osteopetrosis, a disease usually associated with short stature and normal GH/IGF1 axis. Curiously, the patient exhibited normal height development in spite of GH deficiency. Further studies are necessary to evaluate the role of growth factors production and action on bone microenvironment in this condition. Preliminary molecular studies were performed and confirmation of the mutation and its clinical correlation are ongoing.

Disclosure: The authors declared no competing interests.