A trisomy with a karyotype of 47,XXX -- a female with an extra X-chromosome. The old description of 'super female' is misleading, because fertility, if affected, is most likely reduced; primary ovarian failure is more common than with a normal chromosome complement and premature menopause then follows.

A chromosome that's either the X-chromosome (a pair confers femaleness in a normal diploid complement of chromosomes) or the Y-chromosome (just one confers maleness in a normal diploid complement of chromosomes); distinct from the non-sex chromosomes, or autosomes (which are numbered from 1 to 22); aneuploidies give rise to Turner syndrome, Klinefelter syndrome, triple-X syndrome, extra-Y-chromosome syndrome) etc; examined in a karyotype.

An abnormality of the chromosome complement in which there is an extra chromosome seen on the karyotype. The extra chromosome can be an autosome, such as in Down syndrome (trisomy 21), or a sex chromosome, such as triple-X syndrome (47,XXX), Klinefelter syndrome (47,XXY) and extra-Y-chromosome syndrome (47,XYY).