What is a key feature of Turner Syndrome?

Turner Syndrome, a genetic condition affecting females, is characterized by the partial or complete absence of one of the X chromosomes. One of the key features associated with Turner Syndrome is the presence of a cystic hygroma, particularly noted in prenatal ultrasound assessments. This is a fluid-filled sac that develops due to a disruption in lymphatic drainage, and it is often observed in the neck region of fetuses with Turner Syndrome. The presence of cystic hygroma is an important prenatal marker that can lead to further genetic evaluation, as it may indicate chromosomal abnormalities.

In contrast to the other options, macroglossia (enlarged tongue), polydactyly (extra fingers or toes), and spina bifida (a defect in the spinal closure) are not typical features of Turner Syndrome. While they may be associated with other genetic syndromes or conditions, cystic hygroma stands out as a recognizable and relevant finding in Turner Syndrome cases, linking it closely to the clinical presentation of the disorder.