National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Chromosome 21q deletion


Other Names:
Deletion 21q; Monosomy 21q; 21q deletion; Deletion 21q; Monosomy 21q; 21q deletion; 21q monosomy; Partial monosomy 21q See More
Categories:
Chromosome 21q deletion is a chromosome abnormality that occurs when there is a missing copy of the genetic material located on the long arm (q) of chromosome 21. The severity of the condition and the signs and symptoms depend on the size and location of the deletion and which genes are involved. Features that often occur in people with chromosome 21q deletion include developmental delay, intellectual disability, behavioral problems, and distinctive facial features.[1][2] Most cases are not inherited, but people can pass the deletion on to their children. Treatment is based on the signs and symptoms present in each person.
Last updated: 12/16/2015

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • Genetics Home Reference (GHR) contains information on Chromosome 21q deletion. This website is maintained by the National Library of Medicine.
  • 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 21q deletions.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • 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 Chromosome 21q deletion. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.

  1. Monosomy 21. Orphanet. January 2012; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=574.
  2. 21q Deletions. Unique. 2005; http://www.rarechromo.org/information/Chromosome%2021/21q%20deletions%20FTNW.pdf.