1q21.1 Duplications

What does it mean to have a 1q21.1 duplication:

  • Genes provide our body’s instructions and are carried within structures called chromosomes. Sometimes individuals are born with extra or missing sections of chromosomes. A loss or gain of genetic material can impact health, learning, and behavior. The effects may vary based on the location and size of the changes, and the importance of genes there.
    • Those with 1q21.1 duplications have a specific extra section in one of their two chromosome 1's.
  • Individuals with 1q21.1 duplications appear to share an increased risk for developmental problems, which may or may not include autism. The information available about 1q21.1 duplications is limited and families and clinicians share a critical need for more information.

NEW: On June 11, a new paper about individuals was published in a medical journal called "Genetics in Medicine." Researchers used information collected through the Simons VIP Connect study to report new information about this genetic change (also called a "copy number variant.")

Read more about the article here: http://sfari.org/news-and-opinion/news/2015/diverse-features-found-for-autism-linked-chromosome-changes

Read the Simons VIP Summarh here: VIP Summary #6: Clinical phenotype of the recurrent 1q21.1 copy-number variant

  • Children with the duplication tend to have...
    • A larger-than-average head size.
    • Some degree of developmental delay.
      • The most common feature is a fine motor delay or deficit; one example of this may be that people with a 1q21.1 deletion or duplication may take longer to insert a peg into a pegboard.
      • The researchers also saw that people have some trouble understanding and articulating words.
    • The majority of children have some level of cognitive challenge, but most people do not have intellectual disability.
    • About half of the children had a behavioral diagnosis like ADHD or autism.
      • 7 of 19 kids in the study had a clinical diagnosis of autism.
  • Importantly, the researchers didn't notice a distinct "pattern of features' or a "clinical picture," meaning, all of the kids with a 1q21.1 duplication were very different! There are a few key features shared by many of the 19 children studied by Raphael Bernier and his colleagues, but not a defined set of medical or behavioral concerns that doctors and parents can expect to see.
  • However, the duplication is thought to have greater effects on a person's development and brain function than the deletion, as more children with the duplication were diagnosed with autism than in the group of children with the deletion.


1q21.1 Deletions and Duplications Infographic

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