16p11.2 duplication syndrome

Genetic disorder caused by duplication of a segment on chromosome 16

16p11.2 duplication syndrome is a genetic disorder characterized by the presence of an extra copy of a small segment of chromosome 16. This duplication occurs at the 16p11.2 region and can lead to a variety of developmental and health issues. The condition is part of a group of disorders known as copy number variations (CNVs), which involve changes in the number of copies of particular segments of DNA.

Genetics

Autosomal dominant inheritance pattern

The 16p11.2 duplication syndrome is caused by an extra copy of a segment of chromosome 16, specifically at the p11.2 region. This segment is approximately 600 kilobases in size and contains about 25 genes. The duplication can occur de novo, meaning it is a new mutation in the individual, or it can be inherited from a parent. The inheritance pattern is typically autosomal dominant, meaning only one copy of the duplicated segment is sufficient to cause the disorder.

Clinical Features

Individuals with 16p11.2 duplication syndrome may exhibit a range of symptoms, which can vary widely in severity. Common features include:

• Developmental delay
• Intellectual disability
• Speech and language difficulties
• Behavioral problems, such as autism spectrum disorder
• Seizures
• Obesity
• Hypotonia (low muscle tone)

Diagnosis

Diagnosis of 16p11.2 duplication syndrome is typically made through genetic testing, such as chromosomal microarray analysis or whole exome sequencing. These tests can identify the presence of the extra copy of the 16p11.2 region.

Management

There is no cure for 16p11.2 duplication syndrome, and treatment is focused on managing symptoms and improving quality of life. This may include:

• Early intervention programs for developmental delays
• Special education services
• Speech and language therapy
• Behavioral therapy
• Medical management of seizures and other health issues

Prognosis

The prognosis for individuals with 16p11.2 duplication syndrome varies depending on the severity of symptoms. With appropriate interventions and support, many individuals can lead fulfilling lives.

Related pages

• 16p11.2 deletion syndrome
• Copy number variation
• Chromosome 16
• Genetic counseling