Molecular diagnosis in children with fractures but no extraskeletal signs of osteogenesis imperfecta.

In 26 of 94 individuals (28%) below 21 years of age who had a significant fracture history but did not have extraskeletal features of osteogenesis imperfecta (OI), we detected disease-causing mutations in OI-associated genes.

INTRODUCTION: In children who have mild bone fragility but do not have extraskeletal features of OI, it can be difficult to establish a diagnosis on clinical grounds. Here, we assessed the diagnostic yield of genetic testing in this context, by sequencing a panel of genes that are associated with OI.

METHODS: DNA sequence analysis was performed on 94 individuals below 21 years of age who had a significant fracture history but had white sclera and no signs of dentinogenesis imperfecta.

RESULTS: Disease-causing variants were detected in 28% of individuals and affected 5 different genes. Twelve individuals had mutations in COL1A1 or COL1A2, 8 in LRP5, 4 in BMP1, and 2 in PLS3.

CONCLUSIONS: DNA sequence analysis of currently known OI-associated genes identified disease-causing variants in more than a quarter of individuals with a significant fracture history but without extraskeletal manifestations of OI.