Which disorder is associated with an XO chromosomal pattern?

The disorder associated with an XO chromosomal pattern is Turner Syndrome. This condition occurs when a female has only one X chromosome instead of the usual two XX chromosomes. The absence of one X chromosome leads to various physical and developmental features, including short stature, infertility, cardiac issues, and certain physical characteristics such as a webbed neck.

Turner Syndrome is specifically caused by the partial or complete absence of one of the X chromosomes. The term "XO" indicates that there is no second sex chromosome present, which is distinct to this syndrome. This chromosomal pattern is unique to Turner Syndrome and helps differentiate it from other genetic disorders, such as Klinefelter's Syndrome, which involves an extra X chromosome in males (XXY), or Down's Syndrome, which is caused by an extra copy of chromosome 21 (trisomy 21). Sickle Cell Anemia is a genetic blood disorder caused by a mutation in the hemoglobin gene and is not related to chromosomal number abnormalities.