What's osteogenesis imperfecta?
Osteogenesis imperfecta, also called brittle bone disease, is an inherited disorder in which the bones break easily, often from little or no force. It is usually caused by changes in the genes that build type I collagen, the main structural protein of bone. Severity ranges enormously, from a mild tendency to fracture to severe forms with many fractures and bone deformity.
| Also indexed as | OMIM:166200, MONDO:0008146 |
|---|---|
| Features mapped | 15 |
| Treatments mapped | 3 |
| Published sources | 11 |
| Last reviewed | 2026-08-04 |
Signs and symptoms
Blue sclerae
A blue or grey tint to the whites of the eyes (blue sclerae) is a classic sign in many people with osteogenesis imperfecta, caused by the thin collagen letting the dark layer beneath show through. It is harmless in itself but a useful diagnostic clue.
Femoral bowing
In osteogenesis imperfecta the long bones of the legs can curve or bow. The bone is soft and repeated fractures heal unevenly, so deformities of the limbs are common, more so in the more severe forms of the condition.
Dentinogenesis imperfecta
Because teeth also contain collagen, some people have dentinogenesis imperfecta: teeth that are discoloured, weak, and prone to chipping or wear. Dental review and protective care help preserve them.
Growth abnormality
Short stature is one of the most common features of osteogenesis imperfecta, alongside fractures and bony deformities. The soft, easily fractured bone and the deformities that follow can limit normal growth.
Autosomal dominant inheritance
Osteogenesis imperfecta is most often caused by changes in the COL1A1 or COL1A2 genes, which carry the instructions for type I collagen, the main protein scaffold of bone. These changes interfere with collagen and leave the bone fragile.
Hearing impairment
Hearing loss is common and tends to develop in adolescence or adulthood, because the tiny bones of the middle ear are also affected. Regular hearing checks let it be picked up and managed early.
Wormian bones
On a skull X-ray, people with osteogenesis imperfecta often have extra small islands of bone within the joints of the skull, called Wormian bones. They are a helpful diagnostic clue and reflect the abnormal way bone forms in the condition.
Joint hypermobility
Because osteogenesis imperfecta affects collagen, the same protein that gives ligaments their strength, the joints are often unusually loose and flexible. This joint hypermobility can contribute to instability, pain, and a tendency to sprains.
Increased susceptibility to fractures
Osteogenesis imperfecta makes bone fragile, so fractures happen easily and tend to recur, often after little or no force. This bone fragility and the resulting recurrent fractures are the central feature of the condition, and the breaks can lead to lasting bone deformity.
Recurrent fractures
Repeated bone fractures, often from minor bumps or even normal handling in babies, are the central feature. Fracture frequency commonly eases after puberty in milder forms. Prompt orthopaedic care and rehabilitation help protect function and mobility.
Short stature
Many people with osteogenesis imperfecta are shorter than expected for their family. Repeated fractures, curvature of the spine, and the underlying weakness of the collagen that builds bone all limit growth, and short stature is one of the most common features of the more involved types.
Kyphosis
Curvature of the spine, including kyphosis (a forward rounding of the upper back), can develop in osteogenesis imperfecta because the vertebrae are soft and can compress or fracture. Spinal deformities are watched over time and may need bracing or surgery in more severe cases.
Scoliosis
Curvature of the spine (scoliosis) is common in osteogenesis imperfecta because the vertebrae are soft and can compress or fracture. In more severe cases the curve can progress enough to affect breathing and may need bracing or surgery.
Reduced bone mineral density
Bones carry less mineral than normal (low bone mass), which is part of why they are fragile. Bone density is monitored over time and informs decisions about bone-strengthening treatment.
Bowing of limbs due to multiple fractures
In osteogenesis imperfecta the long bones of the arms and legs can curve or bow, both because the bone itself is soft and because repeated fractures heal unevenly. Bowing of the long bones is a visible sign of the bone fragility at the heart of the condition.
How it is diagnosed
Osteogenesis imperfecta, type I
Diagnosed using: COL1A1/COL1A2 genetic testing.
“…diagnosis has evolved from traditional imaging-based assessment to comprehensive evaluation guided by genotype-phenotype…”
Treatment and management
What the research describes, not a recommendation. Treatment decisions belong with your clinician.
This covers treatments that appear in the published research mapped here. Investigational and experimental therapies are not included, so their absence is a boundary of this map, not a sign they do not exist.
bisphosphonates
Bisphosphonates are the main medicines used in osteogenesis imperfecta. They strengthen bone by slowing the cells that break bone down, which can reduce fracture rate and bone pain, especially in moderate-to-severe disease. They do not change the underlying collagen problem, and the decision to use them rests with the specialist team. Physiotherapy, mobility support, and orthopaedic care remain central.
Used to help with: Osteogenesis imperfecta, type I.
“Bisphosphonates play a key role in managing OI.”
bisphosphonates
Bisphosphonates are the main medicine used in osteogenesis imperfecta. They are the primary drug treatment and can reduce how often fractures happen while increasing bone mineral density. They do not fix the underlying collagen problem, and the decision to use them rests with the specialist team.
Used to help with: Osteogenesis imperfecta, type I.
“Bisphosphonates continue to be the primary pharmacologic treatment, effectively reducing fracture risk, and increasing bone mineral…”
supportive care (physical therapy and orthotic support)
Alongside medicine, supportive care is central in osteogenesis imperfecta. Good nutrition, vitamin D, personalized physical therapy, and orthotic support help maintain function and reduce fractures, and there is no cure for the underlying condition.
Used to help with: Osteogenesis imperfecta, type I.
“…good nutrition, vitamin D supplementation, personalized physical therapy, and orthotic support, remains essential for improving function and preventing…”
What changes how it shows up
Carrying the genetic change is not the whole story. The factors below are described in the research mapped here as changing whether, or how strongly, the condition appears. They modulate how the genotype is expressed; they do not, on their own, cause or cure it.
Sillence type (I-IV)
Osteogenesis imperfecta is sorted into clinical types that describe how severe it is. In a large group of adults, type I (the mildest, most common form) made up about three-quarters of people, with the moderate type IV and the more severe type III making up most of the rest. The type a person has helps describe the likely course of the condition.
Described as modulating: Osteogenesis imperfecta, type I.
“266 (76.2%) had type I OI, 55 (15.8%) had type IV, and 19 (5.4%) had type…”
How to read the evidence labels
Where this comes from
This guide is built from 11 published source(s). Every claim above links back to one of them. Click any source ID to read the original on PubMed.
Take it further
Printed, source-linked documents built from this condition's graph — ready to bring to an appointment or attach to a coverage request. Every claim carries its published source, the same as this guide.