A New COL1A1 Mutation Associated With Type I Osteogenesis Imperfecta: Treatment Options for a Woman of Childbearing Age

Abstract

Osteogenesis imperfecta (OI) is a rare heritable skeletal dysplasia, clinically characterized by abnormal bone fragility and predisposition to fractures. Here, we describe the case of a 30-year-old woman harboring a novel frameshift variant in the COL1A1 gene, causing a mild but characteristic phenotype of type I OI. She has blue sclerae, a medical history of fractures during infancy and puberty, a vertebral fracture at a young age, and joint hypermobility. The mutation, c.108del (p.Pro37GInfs*37), causes a premature stop codon insertion, predicted to lead to an unstable mRNA, with a consequent reduction in type I collagen quantity. At present, little is known about the evolution of this phenotype during pregnancy, lactation, and premenopause, conditions that could increase the risk of fractures. Management of type I OI in a young woman of childbearing potential is problematic because most antiosteoporotic drugs are contraindicated in pregnancy, as discussed in our brief review.