Which chromosomal abnormality leads to Turner syndrome?

Turner syndrome is caused by the presence of a single X chromosome in females, leading to the chromosomal configuration known as XO. This means that instead of the typical two sex chromosomes (XX for females), individuals with Turner syndrome have only one X chromosome and an absence of a second sex chromosome. This genetic condition results in various physical and developmental features, such as short stature, delayed puberty, and infertility.

The other chromosomal configurations: XXY is indicative of Klinefelter syndrome, which affects males; XXX represents a condition known as Trisomy X, which often has mild effects; and XYY is associated with male individuals who might be taller than average but also present with different clinical features. Understanding the specific chromosomal makeup helps clarify why XO is directly linked to Turner syndrome.