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Definition
By Mayo Clinic staffTriple X syndrome is an abnormality of the chromosomes that affects about 1 in 1,000 females. Females normally have two X chromosomes, one from each parent. In triple X syndrome, a female has three X chromosomes — hence, the name.
Triple X syndrome usually results from an error in the formation of a mother's egg cell or a father's sperm cell. Sometimes, triple X syndrome occurs as a result of an error early in the embryo's development.
Many girls and women with triple X syndrome have no symptoms or only mild symptoms. In other cases, symptoms may be more pronounced — possibly including developmental delays.
Treatment for triple X syndrome depends on which symptoms, if any, your daughter exhibits and their severity.
- Triple X syndrome. U.S. National Library of Medicine's Genetics Home Reference. http://ghr.nlm.nih.gov/condition/triple-x-syndrome. Accessed Sept. 9, 2012.
- 47 XXX syndrome. Genetics and Rare Diseases Information Center. http://rarediseases.info.nih.gov/GARD/Condition/5672/47_XXX_syndrome.aspx. Accessed Sept. 9, 2012.
- Afshun A. Triple X syndrome. Journal of the Pakistan Medical Association. 2012;62:392.
- Otter M, et al. Triple X syndrome: A review of the literature. European Journal of Human Genetics. 2010;18:265.
- Chromosome abnormalities. National Human Genome Research Institute. http://www.genome.gov/11508982#6. Accessed Sept. 10, 2012.
- Chromosomal abnormalities. March of Dimes. http://www.marchofdimes.com/baby/birthdefects_chromosomal.html. Accessed Sept. 11, 2012.
- Tartaglia NR, et al. A review of trisomy X (47,XXX). Orphanet Journal of Rare Diseases. 2010;5:8.
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