Triple X syndrome is an abnormality of the chromosomes that affects about 1 in 1,000 females. In triple X syndrome, a female has three X chromosomes — hence, the name.
Triple-X syndrome is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). Approximately 0.10% or 1 per 1,000 newborn girls suffer from triple X syndrome.
While the extra X chromosome can of course never be removed, early intervention, such as speech or physical therapy, can help, as well as counselling as girls enter adolescence.
Most of the research that has been published on Triple X Syndrome focuses on case studies and medical/physiological data on patients with Triple X Syndrome.