Which of the following is NOT a characteristic feature of Noonan syndrome?

In the context of Noonan syndrome, distinguishing between characteristic features and those that are not is essential. Noonan syndrome is a genetic disorder that presents with various physical features and associated health issues. Among the common features of Noonan syndrome are short stature, a shield-shaped chest, and coarctation of the aorta.

Short stature is prevalent in individuals with Noonan syndrome due to growth hormone deficiencies or other developmental factors. The shield chest, characterized by a broad and wide thorax, is another identifiable trait associated with the syndrome. Coarctation of the aorta, a condition where the aorta is narrowed, often occurs in individuals with Noonan syndrome and significantly impacts cardiovascular health.

Pectus excavatum, on the other hand, refers to a congenital deformity of the chest wall resulting in a sunken appearance of the sternum. While it can be seen in various genetic and non-genetic conditions, it is not a defining characteristic of Noonan syndrome. Instead, it is more commonly associated with other syndromes like Marfan syndrome. Therefore, its absence from the key features of Noonan syndrome establishes it as not being characteristic of this condition.