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Reviewed October 2014
What is 16p11.2 duplication?
16p11.2 duplication is a chromosomal change in which a small amount of genetic material within chromosome 16 is abnormally copied (duplicated). The duplication occurs near the middle of the chromosome at a location designated p11.2. This duplication can have a variety of effects in affected individuals. The most common characteristics seen in people with a 16p11.2 duplication include a low weight and a slightly small head size; affected individuals also have an increased risk of behavioral problems. However, some people with the duplication have no identified physical or behavioral abnormalities.
Developmental delay and intellectual disability can occur in people with a 16p11.2 duplication, but most have normal intelligence. Affected individuals can also have features of autism spectrum disorders, including impaired communication and socialization skills, as well as delayed development of speech and language. Both expressive language skills (vocabulary and the production of speech) and receptive language skills (the ability to understand speech) can be affected in people with a 16p11.2 duplication. This chromosomal change is also associated with an increased risk of behavioral problems, such as attention deficit hyperactivity disorder, and mental health problems, including schizophrenia, anxiety, and depression. Recurrent seizures are possible in this condition, although they do not occur in most affected individuals.
Some individuals with a 16p11.2 duplication have physical abnormalities such as a slightly small head or malformations of the kidneys and urinary tract. People with this chromosomal change are also at increased risk of being underweight compared with the general population. However, there is no particular pattern of physical abnormalities that characterizes 16p11.2 duplications; signs and symptoms related to the chromosomal change vary even among affected members of the same family.
How common is 16p11.2 duplication?
16p11.2 duplications have been estimated to occur in about 3 in 10,000 people. These changes are present in about 4 in 10,000 people who have mental health problems or difficulties with speech and language. Many people with the duplication are likely never diagnosed because there are many causes of these problems, and some people with the duplication have no related health or developmental problems.
What are the genetic changes related to 16p11.2 duplication?
People with a 16p11.2 duplication have an extra copy of a segment of genetic material on the short (p) arm of chromosome 16 at a position known as p11.2. This duplication affects one of the two copies of chromosome 16 in each cell. The length of the duplicated segment is most often about 600,000 DNA building blocks (base pairs), also written as 600 kilobases (kb). The 600 kb region contains more than 25 genes, and little is known about the function of most of these genes. Researchers are working to determine how the extra genetic material contributes to the features of 16p11.2 duplication.
Read more about chromosome 16.
Can 16p11.2 duplication be inherited?
16p11.2 duplications have an autosomal dominant inheritance pattern, which means that a duplication in one copy of chromosome 16 in each cell is sufficient to cause the condition. Most affected individuals inherit the duplication from one affected parent; they may have similar characteristics of the condition as the parent, or they may be either more or less severely affected. However, in some cases 16p11.2 duplications are not inherited. Instead, they occur as random events during the formation of reproductive cells (eggs and sperm) or in early fetal development. People with a new duplication typically have no history of related signs or symptoms in their family, although their children can inherit the chromosomal change.
Where can I find information about diagnosis or management of 16p11.2 duplication?
These resources address the diagnosis or management of 16p11.2 duplication and may include treatment providers.
- Boston Children's Hospital: Autism Spectrum
- National Institute on Deafness and Other Communication Disorders (NIDCD): Speech and Language Developmental
You might also find information on the diagnosis or management of 16p11.2 duplication inEducational resources and Patient support.
General information about the diagnosis and management of genetic conditions is available in the Handbook.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.
Where can I find additional information about 16p11.2 duplication?
You may find the following resources about 16p11.2 duplication helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
What other names do people use for 16p11.2 duplication?
- autism, susceptibility to, 14B
- 16p11.2 duplication syndrome
- 16p11.2 microduplication
What if I still have specific questions about 16p11.2 duplication?
Where can I find general information about genetic conditions?
The Handbook provides basic information about genetics in clear language.
- What does it mean if a disorder seems to run in my family?
- What is a chromosome?
- Can changes in the number of chromosomes affect health and development?
- Are chromosomal disorders inherited?
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding 16p11.2 duplication?
anxiety ; attention deficit hyperactivity disorder ; autism ; autosomal ; autosomal dominant ; cell ;chromosome ; depression ; developmental delay ; disability ; DNA ; duplication ; hyperactivity ;inherit ; inheritance ; inheritance pattern ; inherited ; kb ; population ; reproductive cells ;schizophrenia ; spectrum ; sperm ; susceptibility ; syndrome
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (7 links)
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.