Osteogenesis Imperfecta (OI) is a group of genetically heterogenous disorders leading to variable phenotypes. It is the most common inherited form of bone fragility and affects 1 in 10,000 to 20,000 births [1]. Most cases are inherited in an autosomal dominant manner and are caused by mutations in the COL1A1 or COL1A2 genes, which encode type 1 collagen [2]. The hallmark of OI is fragility fractures [2]. OI type 1 is the mildest form and is characterised by decreased bone density, increased fractures predominantly in long bones, joint laxity, blue sclerae and hearing loss [3] Dentinogenesis imperfecta may also occur. We present a 56-year-old male (height 167cm) with blue sclerae and severe osteoporosis (FN T-score -4.0 SD). He had a history of frequent joint dislocations in his youth (knees and ankles with rugby, shoulders with sneezing). There was no history of symptomatic fragility fractures. He had reduced hearing and normal dentition. He had been treated with alendronate for 5 years and denosumab for 2 years without improvement in bone density. There was no history of fractures or blue sclerae in his parents or two siblings, and he had no children. A thoraco-lumbar spine xray showed mild thoracic kyphoscoliosis and 40% loss of height of T7. Secondary osteoporosis screen was negative. Genetic screening of the Brittle Bone panel of 19 genes revealed a heterozygous c.380G>A variant in the COL1A2 gene, which results in a Gly127Asp substitution in the triple-helix domain. There are only 2 previous reports of this mutation in the OI database [4,5]. This patient exhibits some features commonly associated with OI type 1. However, the history of frequent dislocations without increased clinical fractures, despite a low bone density, is unusual. This rare gene variant of OI may represent a mild and unique phenotype of type 1 OI.