Sex chromosome aneuploidies are genetic diseases caused by the presence or absence of a sex chromosome. The 23rd pair of chromosomes determine the sex of an individual. Women have two X chromosomes and men have one X and one Y chromosome. There are four major sex chromosome aneuploidies:
Turner syndrome is characterized by the presence of a single X chromosome.
Triple X syndrome is characterized by the presence of three X chromosomes.
Klinefelter syndrome is characterized by the presence of two X chromosomes and one Y chromosome.
Jacob syndrome is characterized by the presence of one X chromosome and two Y chromosomes