Treatments/Programs

Skeletal dysplasias are a mixed group of more than 380 disorders that are marked by abnormalities of cartilage and bone growth. These disorders cause abnormalities in the shape and size of the skeleton and make the long bones, spine and head disproportionate to the rest of the body. Most of these conditions cause a person to be unusually short. (If a person is short, but his or her body parts are in proportionate to each other, the condition may be a result of endocrine or metabolic disorders or nonskeletal dysplasia genetic defects.)

Skeletal dysplasias differ in their natural histories, outcome expectations, inherited patterns and physical mechanisms. Since 2005, when the International Nomenclature and Classification of the Osteochondrodysplasias was revised, these disorders have been organized based on recently information about the gene and/or protein defect that is involved in causing them. Despite this effort, the basic causes underlying many of these disorders are not known. However, with the ever-growing molecular discoveries, how these disorders are named and grouped is being updated constantly.

In the United States, one baby out of every 4,000 to 5,000 is born with a skeletal dysplasia. The four most common skeletal dysplasias are:

  • Achondrogenesis
  • Achondroplasia (the most common, non-lethal skeletal dysplasia)
  • Osteogenesis imperfecta
  • Thanatophoric dysplasia
Thanatophoric dysplasia and achondrogenesis account for 62% of all the lethal skeletal dysplasias at birth. Among infants with skeletal dysplasias detected at birth, 13% are stillborn and 44% die shortly after birth. With certain types of skeletal dysplasias, a child can grow up to have a normal or near-normal life span. This outcome depends on the degree of skeletal abnormalities and related conditions. All people with skeletal dysplasia have some physical impairment because of the condition. However, only in severe situations do these impairments prevent an individual from getting an education or having a career or job.

Usually skeletal dysplasias are identified just after a child is born or during infancy; however, some disorders don't show up until later in childhood. Precise diagnosis is essential to provide genetic counseling and appropriate management and to minimize any disabilities or complications.

Resources for Patients and Families

Additional Cedars-Sinai Resources

print button

WP1