Which disorder is characterized by the absence of one X chromosome?

Turner's syndrome is characterized by the presence of a single X chromosome in females, resulting in a total of 45 chromosomes instead of the usual 46. This condition occurs when one of the X chromosomes is either completely absent or partially missing. Individuals with Turner's syndrome often exhibit various physical traits and may experience a range of developmental challenges, including short stature, delayed puberty, and potential heart and kidney issues. The absence of one X chromosome disrupts typical sexual development and can affect other bodily systems as well.

In contrast, Klinefelter's syndrome involves the presence of an extra X chromosome in males (XXY), Down's syndrome is caused by an extra copy of chromosome 21, and Fragile X syndrome is linked to a mutation on the X chromosome, leading to intellectual disabilities and behavioral challenges. Each of these conditions has distinct chromosomal profiles and associated characteristics.