ESPE Abstracts

Background: A 3-year-old boy appeared healthy at birth and did not experience any fractures until 12 months of age. Blue sclera, frequent fractures without adequate trauma, nearly normal stature, the absence of dentinogenesis imperfecta, no bony deformity, and no limitation of mobility were characteristics suggestive of OI type I that were observed in the patient. The patient’s mother had blue sclera and a history of frequent fracture episodes until the age of 15 years.

Objective and hypotheses: These findings suggested OI type 1. We performed genetic testing to identify type and mutation of OI, and pamidronate was tried to examine its effectiveness.

Method: Genetic testing and cyclic treatment of pamidronate was performed.

Results: A novel COL1A1 missense mutation (c.2T>G) was found in the patient and his mother, and this is the first such case reported in the literature. After 1 year of treatment, the bone mineral density increased in lumbar spine and femur neck, and radiography showed laminatic sclerosis at distal metaphysis of tibia, fibula and femur, so called zebra stripe sign from cyclic bisphosphonate treatment. There has been no fracture till 1.5 year after pamidronate treatment.

Conclusion: This is a clinical and radiological findings of one Korean patient with OI type I with a novel mutation in the start codon of COL1A1 (c.2T>G) disrupting the start codon of the gene (ATG to AGG (Met1Arg)). Identification of this mutation expands the knowledge and significance of the start codon of the COL1A1 gene in the pathogenesis of OI type I. The pamidronate was effective in preventing fracture in this patient.

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