Triple-X syndrome
Background
Triple-X is a chromosomal condition which occurs only in females. A chromosome is a rod-like structure present in the nucleus of all body cells, with the exception of the red blood cells, which stores genetic information. Normally humans have twenty-three pairs of chromosomes, forty-six chromosomes in total. The twenty-third pair, otherwise referred to as the sex chromosomes, stores genetic information which determines our sex. A male has a XY pair and a female has a XX pair of chromosomes.
A female affected by triple-X syndrome has an XX pair of chromosomes, as well as additional X chromosome, resulting in the formation of XXX. A mosaic form also occurs where only a percentage of body cells contain XXX while the remainder carry XX. The extent to which an individual is affected by the condition will depend upon the proportion of XXX to XX throughout.