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22q13.3 deletion syndrome

Other Names for this Disease
  • Chromosome 22q13.3 deletion syndrome
  • Deletion 22q13.3 syndrome
  • Monosomy 22q13
  • Phelan-McDermid syndrome
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22q13.3 deletion syndrome, also known as Phelan-McDermid syndrome, is a chromosome abnormality caused by the loss (deletion) of a small piece of chromosome 22. The deletion occurs near the end of the long arm (or q arm) at a location designated as q13.3. The signs and symptoms of this condition vary widely from person to person. Common symptoms include low muscle tone (hypotonia), intellectual disability, delayed or absent speech, abnormal growth, tendency to overheat, large hands, and abnormal toenails. Affected individuals may have characteristic behaviors, such as mouthing or chewing on non-food items, decreased perception of pain, and autistic-like behaviors. The loss of a particular gene on chromosome 22, called the SHANK3 gene, is likely responsible for many of the signs and symptoms of 22q13.3 deletion syndrome. Additional genes within the deleted region probably contribute to the variable features of the syndrome.[1][2]
Last updated: 12/6/2011


  1. Phelan K & Rogers C. 22q13.3 Deletion Syndrome. GeneReviews. August 2011; Accessed 12/6/2011.
  2. 22q13.3 deletion syndrome. Genetics Home Reference. September 2009; Accessed 12/6/2011.
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Basic Information

  • Genetics Home Reference (GHR) contains information on 22q13.3 deletion syndrome. This website is maintained by the National Library of Medicine.
  • The National Organization for Rare Disorders (NORD) is a federation of more than 130 nonprofit voluntary health organizations serving people with rare disorders. Click on the link to view information on this topic.
  • Unique is a source of information and support to families and individuals affected by rare chromosome disorders. Click on the link to view information about 22q13.3deletion syndrome.

In Depth Information

  • The Online Mendelian Inheritance in Man (OMIM) is an catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs.  Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss 22q13.3 deletion syndrome. Click on the link to view a sample search on this topic.

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