Your browser does not support javascript:   Search for gard hereSearch for news-and-events here.


Genetic and Rare Diseases Information Center (GARD)

Print friendly version

47, XYY syndrome

Other Names for this Disease
  • Jacobs syndrome
  • XYY Karyotype
  • XYY syndrome
  • YY syndrome
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.


47, XYY syndrome is characterized by an extra copy of the Y chromosome in each of a male's cells. Males with this condition typically do not have unusual physical features and usually have normal sexual development and are able to father children. Signs and symptoms vary widely among affected males and may include being taller than average; an increased risk of learning disabilities and delayed speech and language skills; delayed motor skills (such as sitting and walking); weak muscle tone (hypotonia); hand tremors or other involuntary movements (motor tics); and behavioral and emotional difficulties. A small percentage of males with 47, XYY syndrome are diagnosed with autism spectrum disorders. Most cases are not inherited.[1]
Last updated: 1/5/2012


  1. 47,XYY syndrome. Genetics Home Reference. January 2009; Accessed 4/29/2011.
Your Questions Answered
by the Genetic and Rare Diseases Information Center

1 question(s) from the public on 47, XYY syndrome have been answered. See questions and answers. You can also submit a new question.

Basic Information

In Depth Information

  • 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 47, XYY syndrome. Click on the link to view a sample search on this topic.