His mother and maternal aunt both have scoliosis. His mother fractured her ankle once. Genetic studies were sent to a specialized reference lab for confirmation. I is characterized by osteoporosis and excessive bone fragility, blue sclerae and hearing loss in adolescents and young adults. This is the most common form of osteogenesis imperfecta with an incidence of about 1 in 30,000 live births.
Inheritance is autosomal dominant.
Minimal trauma may result in fractures. Radiographs show generalized osteopenia and healing fractures. Skin fibroblasts from patients show a reduction of type I procollagen synthesis. Most cases are new mutations, but some are autosomal recessive occurring in 1 in 60,000 live births. The skull is soft and the limbs are short.