Achondrogenesis type II is a rare genetic disorder that affects bone growth and development. It is also known as Langer-Saldino syndrome or lethal neonatal dwarfism.
Individuals with achondrogenesis type II typically have short limbs and an abnormally small chest, which can lead to respiratory difficulties. They may also have a small head with a prominent forehead and a flat face. Infants with the condition are often born with a soft skull and may have an enlarged liver and spleen.
The disorder is caused by mutations in the COL2A1 gene, which provides instructions for making a protein called type II collagen. This protein is essential for the formation of bones and other connective tissues. Mutations in the COL2A1 gene lead to a deficiency or dysfunction of type II collagen, which impairs bone growth and development.
Achondrogenesis type II is inherited in an autosomal dominant pattern, which means that a person with one copy of the mutated gene will have the disorder. In some cases, the condition may occur spontaneously due to a new mutation in the gene.
There is no cure for achondrogenesis type II, and treatment is generally supportive and aimed at managing symptoms. Prenatal diagnosis may be possible through genetic testing for families with a history of the condition.