22q11.2 distal deletion syndrome

22q11.2 distal deletion syndrome is a rare genetic disorder caused by a small missing piece (deletion) of chromosome 22. The deletion occurs near the middle of the chromosome at a location designated q11.2.

Symptoms

The symptoms of 22q11.2 distal deletion syndrome can vary widely, even among members of the same family. Common symptoms include intellectual disability, developmental delay, and distinctive facial features. Some affected individuals also have heart defects, kidney abnormalities, and/or other physical health problems.

Causes

22q11.2 distal deletion syndrome is caused by a deletion of approximately 200,000 to 2 million DNA building blocks (base pairs) in the long arm of chromosome 22. The deletion includes at least 30 genes, many of which have not been well characterized. It is unclear how the loss of these genes leads to the specific features of 22q11.2 distal deletion syndrome.

Diagnosis

Diagnosis of 22q11.2 distal deletion syndrome is typically made through a blood test that can identify the missing piece of chromosome 22. This test, known as a fluorescence in situ hybridization (FISH) test, is highly accurate and can confirm a diagnosis in individuals with suspected 22q11.2 distal deletion syndrome.

Treatment

There is currently no cure for 22q11.2 distal deletion syndrome. Treatment is symptomatic and supportive, and may include regular monitoring of growth and development, educational support, and therapies to address any physical or mental health concerns.

Prognosis

The prognosis for individuals with 22q11.2 distal deletion syndrome varies depending on the severity of symptoms. With appropriate support and treatment, many individuals with this condition can lead healthy, productive lives.

See also

• Chromosome 22
• Genetic disorder
• Fluorescence in situ hybridization