What are the main symptoms of osteogenesis imperfecta?
The symptoms of osteogenesis imperfecta (OI) can be very different among people with the disorder. This is true even for people in the same family. Some people are severely impacted by the disorder, while others may function normally without problems. The characteristic symptom are bones that fracture repeatedly despite little or no trauma or cause, although some people may have very few fractures during their lives.
As of April 2017, and depending on the medical source, OI is classified into anywhere from 9 to 15 subtypes based on the altered gene, x-ray (radiographic) findings, and signs and symptoms. OI types I-IV are the most common and are caused by changes in one of two genes, either the COL1A1 or COL1A2 genes.
OI type I is a milder form. Fractures may occur during infancy when diapering. More likely, fractures may first occur when an infant begins to walk, usually from falling. Children may have a few to several fractures per year. The frequency of fractures often decreases after puberty. Infants or children may also have a bluish discoloration of the whites of the eyes; this is called blue sclera. About half the people with this form will develop hearing loss as adults.
OI type II is a severe form and can be fatal just before or just after birth. There are frequent, severe fractures and the arms and legs are short and often bowed. The skin is fragile. Bone problems involving the ribs or other bones of the chest can prevent the lungs from functioning properly. This can lead to respiratory failure.
OI type III is often severe and fractures are common in infancy, including from simple interactions with the infant. These means fractures can occur from simply holding the infant in a normal manner, or when diapering, or picking up an infant. Some people are at risk for breathing complications and respiratory failure. Children and adults may need assistance to walk, which can include braces, canes, or scooters or wheelchairs. Growth is affected and when people with OI type III reach adulthood, their final height may be very short. The teeth may also be affected, and hearing loss is common and often begins in the teen-age years.
The severity of OI types IV, V, VI, VII, VIII, and IX can be very different and fall somewhere in between the usually milder type I and the very severe type II.
There are additional symptoms that some people with OI may have. Many adults with OI develop hearing loss. Some people with moderate forms of the disorder may be very short when they reach their final heights (short stature). Some individuals have joints that have an abnormally large range of movement or are prone to dislocation, joint pain, early onset arthritis, loose or fragile skin, or abnormally curved spines. Some people have loose ligaments; ligaments are the tough, elastic bands of connective tissue that connect two bones or hold together a joint. Some doctors suggest that problems with the heart and blood vessels, called the cardiovascular system, are more common in people with OI than in people without it, but other doctors are not sure that this is true.
Some people have a condition called dentinogenesis imperfecta. This condition causes the teeth to be discolored, usually bluish-gray or yellowish-brown. The teeth wear away, break or fall out easily.
SOURCE: Emory University - Department of Human Genetics in collaboration with ThinkGenetic • https://www.thinkgenetic.com/diseases/osteogenesis-imperfecta/symptoms/27303 • DATE UPDATED: 2017-04-17
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Steiner RD, Adsit J, Basel D. COL1A1/2-Related Osteogenesis Imperfecta. GeneReviews website. Accessed April 6, 2017. https://www.ncbi.nlm.nih.gov/books/NBK1295/
Osteogenesis Imperfecta Overview. NIH Osteoporosis and Related Bone Diseases National Resource Center website. https://www.niams.nih.gov/Health_Info/Bone/Osteogenesis_Imperfecta/overview.asp
Osteogenesis Imperfecta. The Genetics Home Reference website. Accessed April 6, 2017. https://ghr.nlm.nih.gov/condition/osteogenesis-imperfecta