What is the most likely diagnosis for a full-term female newborn presenting with a cystic hygroma?

A cystic hygroma is a fluid-filled sac that occurs due to lymphatic malformations, and it is commonly associated with a number of congenital conditions. Among the various conditions linked to cystic hygromas, Turner syndrome (gonadal dysgenesis 45,X) is particularly notable.

Turner syndrome is characterized by the complete or partial absence of one of the X chromosomes, leading to a variety of physical and developmental challenges. Cystic hygromas are frequently observed in fetuses with Turner syndrome, and their presence can be an important prenatal marker suggestive of this diagnosis.

In the case of a full-term newborn exhibiting a cystic hygroma, the likelihood of Turner syndrome is elevated, especially given that it tends to present with distinctive physical features as the infant grows, such as short stature, webbed neck, and gonadal dysgenesis.

Other conditions listed, like cystic fibrosis and Down syndrome, have their own characteristic presentations and associated anomalies, but they are not typically linked with cystic hygromas in the same way that Turner syndrome is. Amniotic band syndrome typically results in disruptive limb defects and does not generally manifest as a cystic hygroma. Therefore, the presence of the cystic hyg