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

Ring chromosome 9



Other Names:
Chromosome 9 ring; Ring 9; R9
Categories:

Ring chromosome 9 is a very rare chromosome abnormality in which the ends of chromosome 9 join together to form a ring shape. The resulting ring may be missing genes, or it may contain extra copies of genes. Therefore, the severity and symptoms associated with ring chromosome 9 vary from person to person. Signs and symptoms that may be present in a person with ring chromosome 9 include slow growth and short stature, learning disabilities, small head size, distinctive facial features, low muscle tone (hypotonia), skeletal abnormalities, and/or other birth defects involving various parts of the body. However, people with ring chromosome 9 can be generally healthy and have no major birth defects.[1]

Ring chromosome 9 typically is not inherited and occurs sporadically, during the formation of egg or sperm cells or shortly after the egg and sperm join together. Occasionally, one of the parents has a chromosome abnormality involving chromosome 9. Chromosome testing of both parents can help determine whether the ring chromosome was inherited and whether future children have an increased chance to have a chromosome abnormality.[1] Treatment for ring chromosome 9 depends on the signs and symptoms present in each person.
Last updated: 5/29/2018

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

  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.
  • 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 ring chromosome 9.

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 Ring chromosome 9. Click on the link to view a sample search on this topic.

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