Learn more. Osteogenesis imperfecta OI is an inherited genetic bone disorder that is present at birth. It is also known as brittle bone disease. A child born with OI may have soft bones that break fracture easily, bones that are not formed normally, and other problems. Signs and symptoms may range from mild to severe. The main goal of treatment is to prevent deformities and fractures. OI is a lifelong condition. There are at least 8 different types of the disease.
The types vary greatly, both within and between types. They are based on the type of inheritance see below , and signs and symptoms. These include findings on X-rays and other imaging tests. The OI types are as follows:. Type I. Mildest and most common type. There are few fractures and deformities. Type II. Most severe type. A baby has very short arms and legs, a small chest, and soft skull. He or she may be born with fractured bones.
He or she may also have a low birth weight and lungs that are not well developed. A baby with type II OI usually dies within weeks of birth. Type III. At birth, a baby may have slightly shorter arms and legs than normal and arm, leg, and rib fractures.
A baby may also have a larger than normal head, a triangle-shaped face, a deformed chest and spine, and breathing and swallowing problems. These symptoms are different in each baby. Type IV. Symptoms are between mild and severe. A baby with type IV may be diagnosed at birth. He or she may not have any fractures until crawling or walking. The bones of the arms and legs may not be straight. He or she may not grow normally.
Type V. Similar to type IV. Symptoms may be medium to severe. It is common to have enlarged thickened areas hypertrophic calluses in the areas where large bones are fractured. Type VII. May be like type IV or type II. It is common to have shorter than normal height. Also common to have shorter than normal upper arm and thighbones.
Type VIII. Very soft bones and severe growth problems. OI is passed on through the genes. The different types are passed on in different ways.
The gene may be inherited from one or both parents. Or the gene can be passed on from an unexplained change spontaneous mutation of a gene. They can direct you to research, resources, and services. Inclusion on this list is not an endorsement by GARD. These resources provide more information about this condition or associated symptoms.
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Other Names:. Congenital and Genetic Diseases. Summary Summary. Symptoms Symptoms. Showing of 89 View All. Abnormality of tooth color. Abnormality of tooth shade. Abnormal tooth enamel.
Enamel abnormalities. Enamel abnormality. Abnormality of the wide portion of a long bone. Abnormality of the shankbone.
Abnormality of the shinbone. Short and broad skull. Dental cavities. Tooth cavities. Tooth decay. Beaked nose. Beaklike protrusion.
Hooked nose. Polly beak nasal deformity. Decreased bone formation of skull. Thickening of shaft or central part of long bones. Prenatal growth deficiency. Prenatal growth retardation. Little lower jaw. Small jaw. Small lower jaw. Hearing loss, mixed. Mixed hearing loss. Pigeon chest. Prominent back of the skull. Prominent posterior skull. Slender ribs. Whites of eyes are a bluish-gray color. Loose and inelastic skin.
Bad bite. Malalignment of upper and lower dental arches. Misalignment of upper and lower dental arches. Bowed thighbone. Knock knees. Elevated urine calcium levels. Excessive sweating. Increased sweating. Profuse sweating. Sweating profusely. Sweating, increased. Joints move beyond expected range of motion. Wide fontanelles. Low chest circumference. Narrow shoulders. Long bones slender. Thin long bones. Compression fracture. Impaired vision. Loss of eyesight. Poor vision. Joint pain.
Bruise easily. Easy bruisability. Easy bruising. Delayed eruption. Delayed teeth eruption. Delayed tooth eruption. Many of these genes provide instructions for proteins that help process type I collagen into its mature form. Mutations in these genes disrupt different steps in the production of collagen molecules. These changes weaken connective tissues, leading to severe bone abnormalities and problems with growth. Other genes involved in osteogenesis imperfecta provide instructions for making proteins that control the development and function of bone-forming cells.
Mutations in these genes impair normal bone development, causing the bones to be brittle and to fracture easily. When caused by mutations in the COL1A1 or COL1A2 gene, osteogenesis imperfecta has an autosomal dominant pattern of inheritance, which means one copy of the altered gene in each cell is sufficient to cause the condition. Many people with type I or type IV osteogenesis imperfecta inherit a mutation from a parent who has the disorder.
Most infants with more severe forms of osteogenesis imperfecta such as type II and type III have no history of the condition in their family. Type V is also inherited in an autosomal dominant pattern. Less commonly, osteogenesis imperfecta has an autosomal recessive pattern of inheritance. Autosomal recessive inheritance means two copies of the gene in each cell are altered.
The parents of a child with an autosomal recessive disorder typically are not affected, but each carry one copy of the altered gene.
Osteogenesis imperfecta type XIX is inherited in an X-linked recessive pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes in each cell. In males, who have only one X chromosome, a mutation in the only copy of the gene in each cell is sufficient to cause the condition.
In females who have two X chromosomes , a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. Genetics Home Reference has merged with MedlinePlus. Learn more. The information on this site should not be used as a substitute for professional medical care or advice.
Contact a health care provider if you have questions about your health. Osteogenesis imperfecta.
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