Diseases Studied
The Rare Diseases Clinical Research Network is an NIH-funded research network of 21 active consortia or research groups working to advance treatment for diseases that are rare. Use the search tools on this page to find the diseases we currently study. You can reach out to the indicated consortia or research groups for more information on those diseases and studies underway.
This network focuses on clinical research and does not generally support clinical care outside of research activities. To learn about other rare diseases, please visit the Genetic and Rare Diseases Information Center (GARD), which is an NIH program that helps the public find reliable information about rare and genetic diseases. Their staff are specialists. Contact them at 1-888-205-2311 or email GARDinfo@nih.gov.
All Diseases > XXYYY syndrome
XXYYY syndrome
Alternative Names: 49,XXYYY; 2X 3Y syndrome
Disease Category: Sex Chromosome Aneuploidy
XXYYY syndrome, also known as 49,XXYYY or "2X 3Y syndrome", is an extremely rare sex chromosome aneuploidy characterized by the presence of two extra Y chromosomes and one extra X chromosome in males, resulting in a total of 49 chromosomes. Its prevalence is exceedingly low, with only a handful of postnatal cases reported in the medical literature.
Research groups studying this disease
Sex Chromosome Aneuploidy
Network for Advancing Sex Chromosome Aneuploidy Research Readiness (NASCARR)
Association for X and Y Chromosome Variations (AXYS)
The mission of AXYS is to help individuals with one or more extra X and/or Y chromosomes and their families to lead fuller, more productive lives.
Chromodiversity Foundation
The Chromodiversity Foundation aims change how the world perceives and supports genetic differences and to help kids and families navigate their unique journeys with confidence and understanding.