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Chromosome 16p11.2 duplication syndrome

MedGen UID:
Concept ID:
Disease or Syndrome
Monarch Initiative: MONDO:0013847
OMIM®: 614671
Orphanet: ORPHA370079


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. Common characteristics that occur in people with a 16p11.2 duplication include a low weight; a small head size (microcephaly); and developmental delay, especially in speech and language. 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. Approximately one-third of children with this condition have delays in developing physical skills such as sitting, crawling, or walking. The average IQ of affected individuals is about 26 points lower than that of their parents without the duplication. About 80 percent of people with a 16p11.2 duplication have problems related to speech or language. Both expressive language skills (vocabulary and the production of speech) and receptive language skills (the ability to understand speech) can be affected.

One of the most common behavioral problems associated with this chromosomal change is attention-deficit/hyperactivity disorder (ADHD). Autism spectrum disorder, which affects communication and social skills, is diagnosed in about one in five people with a 16p11.2 duplication. Affected individuals also have an increased risk of mental health problems, including schizophrenia, anxiety, and depression. Recurrent seizures are possible in this condition, although they do not occur in most affected individuals.

Other abnormalities that can occur with a 16p11.2 duplication include malformations of the kidneys and urinary tract. 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. [from MedlinePlus Genetics]

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVChromosome 16p11.2 duplication syndrome
Follow this link to review classifications for Chromosome 16p11.2 duplication syndrome in Orphanet.

Professional guidelines


Yang M, Lewis F, Foley G, Crawley JN
Physiol Behav 2015 Jul 1;146:16-27. doi: 10.1016/j.physbeh.2015.04.023. PMID: 26066718

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