Osteogenesis imperfecta

Alternative names:

brittle bone disease

Definition:

A condition of abnormal fragility of the bones.

Causes, incidence, and risk factors:

This serious bone disorder is usually present at birth as an inherited disease. Osteogenesis imperfecta is classified into four types. Type I is autosomal dominant (50% of the children will develop the disorder if one parent has the gene for the disorder). Type II is autosomal dominant but is not seen much because this type is lethal. Type IV is also autosomal dominant. Type III is autosomal recessive (both parents must transmit the gene for the disorder in order for symptoms to develop in the child).

Infants may have multiple fractures which result in shortened arms and legs. The skull may be affected. Trauma to the skull during delivery may result in stillbirth. Infants may die shortly after birth. Mild cases may not be detected until later in life.