Osteogenesis Imperfecta: Types, Symptoms and Treatment

Author: Ian C. Langtree - View Credentials
Published: 4 Apr 2009 - Updated: 13 Oct 2026
Publication Type: Informative

Table of Contents:
Synopsis - Definition - Overview - FAQs - Insights, Updates - Related Content

Synopsis

This information explains osteogenesis imperfecta (OI), the inherited bone condition widely known as brittle bone disease, in which faulty type I collagen leaves bones prone to breaking from minor trauma or no clear cause at all. It covers how the condition ranges from the mild type I form, where fractures mostly happen in childhood and become less common in adulthood, to the severe type II form, where an underdeveloped rib cage and lungs can be life-threatening shortly after birth. It also describes features beyond the skeleton, including blue or gray sclerae, hearing loss that often starts in adulthood, short stature, breathing problems and dentinogenesis imperfecta, a disorder of tooth development. The overview brings together the clinical signs, how the forms are grouped by severity, current U.S. incidence and prevalence figures, and how bisphosphonate drugs are used to reduce pain and fractures, making it a useful reference for people living with OI, parents of children who have been diagnosed, older adults coping with the hearing and bone changes that come later in life, and the teachers, caregivers and clinicians who support them.

At a Glance

• 1 - Severe forms can be seen on ultrasound as early as 16 weeks of pregnancy.
• 2 - The SSA lists OI Type II as a Compassionate Allowance to speed disability claims.
• 3 - Most infants with severe OI have no family history - the cause is a new COL1A1 or COL1A2 mutation.
• 4 - A 2013 Sheffield trial found oral risedronate lowered fracture risk in children aged 4 to 15, with benefits showing after six weeks.

Topic Definition

Osteogenesis Imperfecta

Osteogenesis imperfecta is a group of inherited connective tissue disorders in which the body makes too little type I collagen, or collagen that is structurally faulty, leaving bones fragile and prone to fracture from minimal or no trauma. Most cases come from variants in the COL1A1 or COL1A2 genes, but changes in more than 20 other genes involved in collagen processing and bone formation have also been identified. The condition ranges from mild, with a few fractures over a lifetime, to forms that are fatal around the time of birth. Common features include blue or gray sclerae, short stature, bone deformity, loose joints, hearing loss and dentinogenesis imperfecta. There is no cure, so care focuses on preventing fractures, keeping people mobile and managing related complications.

Overview

Osteogenesis imperfecta (OI) is a group of genetic disorders that mainly affect the bones. The term means imperfect bone formation. Most cases are caused by changes in the COL1A1 or COL1A2 genes, which carry the instructions for making type I collagen, the protein that gives bone its strength and flexibility. When there is too little collagen, or the collagen is faulty, bones become fragile and break easily. Other names for the condition include brittle bone disease, osteogenesis imperfecta congenita, Lobstein disease (a historical name for the mild form, type I) and Vrolik disease (a historical name for the severe form, type II).

The U.S. Social Security Administration (SSA) has included Osteogenesis Imperfecta (OI) - Type II as a Compassionate Allowance to expedite a disability claim.

People with OI have bones that break easily, often from minor trauma or with no apparent cause. Multiple fractures are common and can happen even before birth in severe cases. People with milder forms may have only a few fractures over their lifetime.

Types of Osteogenesis Imperfecta

In 1979, Australian physician Dr. David Sillence grouped OI into four types, numbered I to IV, based on what doctors could see: how often bones broke, how much they bent or deformed, eye color, hearing loss and how the condition ran in families. These four types are still the foundation of how OI is described today.

As genetic testing improved, researchers began finding people whose OI looked similar to the original four types but had different genetic causes. New types were added, starting with type V in the early 2000s. More than 20 types of OI have now been described, linked to changes in more than 20 different genes. Many of the newer types are rare, some found in only a few families, and are inherited in an autosomal recessive pattern, meaning a child inherits a gene change from both parents.

Because most of the newer genetic types look clinically like types II, III or IV, doctors increasingly describe OI by its severity plus the gene involved - for example, OI type III, COL1A2-related - instead of giving every new gene its own number. Using this approach, OI is usually grouped into five clinical types:

• Type I - the mildest and most common form. Bones break easily, but there is little or no bone deformity, and height is normal or near normal.
• Type II - the most severe form. It is usually fatal before or shortly after birth because of breathing problems.
• Type III - the most severe form in people who survive infancy. It causes many fractures, progressive bone deformity and very short stature.
• Type IV - a moderate form, between types I and III in severity, with mild to moderate bone deformity and variable height.
• Type V - a moderate form with distinctive features, such as unusually large calluses at fracture sites and hardening of the membrane between the two forearm bones, which limits turning of the wrist.

The milder forms of OI, including type I, involve fractures during childhood and adolescence that often result from minor trauma. Fractures happen less often in adulthood. People with mild forms often have a blue or gray tint to the white part of the eye (the sclera) and may develop hearing loss in adulthood.

The more severe forms cause frequent fractures that may begin before birth and result from little or no trauma. Other features can include blue sclerae, short stature, hearing loss, breathing problems and dentinogenesis imperfecta, a disorder of tooth development that leaves teeth discolored and weak.

The most severe forms, particularly type II, can include an abnormally small, fragile rib cage and underdeveloped lungs. Infants with these features have life-threatening breathing problems and often die shortly after birth.

Early Detection

Ultrasound can often detect severe cases of OI during pregnancy. Type II can be seen on ultrasound as early as 16 weeks, and genetic testing may be able to identify the gene change responsible. Most infants with severe forms of OI, such as type II, have no family history of the condition. In these infants, OI is caused by a new (sporadic) mutation in the COL1A1 or COL1A2 gene.

Milder forms may not be diagnosed until a child has several fractures, and some people with type I are not diagnosed until adulthood. Diagnosis usually combines a physical exam, family history, X-rays, bone density testing and genetic testing.

Treatment

There is no cure for OI, but treatment can reduce fractures, pain and other complications. Bisphosphonates, drugs originally developed to treat osteoporosis, are now widely used in OI to increase bone density and lower fracture rates, especially in children. They can be given by intravenous infusion, such as pamidronate or zoledronic acid, or taken by mouth, such as risedronate or alendronate.

Care usually also includes physical and occupational therapy to build muscle strength and mobility, surgery to place metal rods in the long bones to straighten them and prevent fractures, hearing aids or ear surgery for hearing loss, and dental care for weak teeth.

Osteogenesis Imperfecta Facts and Statistics

OI causes weak bones that break easily, sometimes for no known reason. It can also cause weak muscles, loose joints, brittle teeth and hearing loss.

• More than 20 types of OI have been identified, but most people fit into the original clinical types I to IV.
• Type I is mild, type II is usually fatal around birth, type III is the most severe form in people who survive infancy, and types IV and V are moderate.
• About 85 to 90 percent of cases are caused by changes in the COL1A1 or COL1A2 genes.
• In the United States, OI is estimated to occur in about 1 in 20,000 births.
• An estimated 25,000 to 50,000 people in the United States have OI.
• Outlook varies widely depending on the type and severity of symptoms. Many people with mild OI have a normal life expectancy.

2013 Study: Oral Risedronate for Children with OI

In 2013, researchers at the University of Sheffield and Sheffield Children's Hospital in England reported results from a trial of oral risedronate, a bisphosphonate, in children with OI. The study was published in The Lancet.

The trial included children with OI aged 4 to 15. It found that oral risedronate lowered the risk of first and repeat clinical fractures, and that the drug was generally well tolerated. The benefit appeared quickly - fracture risk between the treated and untreated groups began to separate after only six weeks of treatment.

The researchers pointed out that because the drug is taken by mouth at home, rather than by an intravenous drip in hospital like other bisphosphonates used for OI, it is a more family-friendly option.

The study was funded by the Alliance for Better Bone Health.

Frequently Asked Questions

How is osteogenesis imperfecta inherited?

Most cases follow an autosomal dominant pattern, so a parent with OI has a 50 percent chance of passing it to each child. Some rarer types are autosomal recessive, meaning both parents carry a gene variant without having the condition themselves.

Can osteogenesis imperfecta be diagnosed in adulthood?

Yes. People with mild type I OI are sometimes not diagnosed until adulthood, often after early hearing loss, repeated fractures or low bone density lead to genetic testing.

Can OI fractures be mistaken for child abuse?

Yes. Unexplained or repeated fractures in young children can raise abuse concerns, which is why a genetic evaluation and review by a specialist familiar with OI are important when a child has frequent breaks.

What is rodding surgery for osteogenesis imperfecta?

Rodding surgery places metal rods inside the long bones, such as the femur or tibia, to straighten them and reduce fractures. Telescoping rods can lengthen as a child grows, which cuts down on repeat surgeries.

What types of exercise are safe for people with OI?

Swimming and water therapy are often recommended because water supports the body and lowers fracture risk. Walking and supervised strength training can also help build muscle and bone, but plans should be tailored by a physical therapist.

Does osteogenesis imperfecta shorten life expectancy?

People with mild OI usually have a normal or near-normal life expectancy. Severe forms carry higher risks, mainly from breathing and heart problems linked to chest wall and spine deformities.

Can women with osteogenesis imperfecta have a safe pregnancy?

Many women with OI have successful pregnancies, but they need care from a high-risk obstetric team. Doctors will review pelvic shape, spine curvature, breathing capacity and whether a cesarean birth is the safer option.

Which doctors treat osteogenesis imperfecta?

Care is usually coordinated by a team that can include an endocrinologist or bone specialist, orthopedic surgeon, geneticist, physical and occupational therapists, audiologist, dentist and pulmonologist.

Insights, Analysis, and Developments

Editorial Note: Osteogenesis imperfecta is rare, but its effects reach well beyond broken bones. Families often deal with repeated hospital visits, careful handling of infants and children, and sometimes doctors or social workers who mistake unexplained fractures for abuse. With roughly 1 in 20,000 births affected and tens of thousands of Americans living with the condition, OI shows why fast diagnosis, genetic testing and well-coordinated care matter so much. Treatment cannot fix the underlying collagen defect yet, but bisphosphonates, physical therapy, surgery to support the long bones, and hearing and dental care now let many people with OI go to school, work, raise families and live long lives. What helps most is a clear understanding of the condition among clinicians, educators and employers, along with homes, schools and workplaces designed with fragile bones in mind.

Author Credentials: Ian C. Langtree is a writer, editor, and the founder and Editor-in-Chief of Disabled World, which he established in 2004 as one of the longest-running independent resources for disability news and information. Over more than two decades, he has written and edited thousands of articles on disability rights, health, accessibility, and assistive technology. Drawing on a global perspective shaped by extensive travel and lived experience, Ian is a committed advocate of the Social Model of Disability, the framework developed by disabled activists in the 1970s that focuses on removing societal barriers rather than on individual impairments. His writing is grounded in that framework and in a lasting commitment to disability rights, accessibility, and social inclusion. To learn more about Ian's background, expertise, and accomplishments, visit his full biography.