Which physical characteristic is commonly associated with Down syndrome?

A simian line, also known as a single transverse palmar crease, is a physical characteristic that is commonly associated with Down syndrome. This line is a single groove that crosses the palm of the hand instead of the typical two creases. While it is not exclusively present in individuals with Down syndrome, its occurrence is more prevalent in this population compared to those without the condition.

The presence of a simian line can be a marker that healthcare professionals look for during assessments. It is important to note that while individuals with Down syndrome may have other features, such as distinct facial characteristics and hypotonia, the simian line is specifically linked to their genetic condition and can serve as a point of identification in screening.

The other options, while they may describe features seen in various populations, are not as closely associated with Down syndrome specifically. For instance, large ears, wide-set eyes, and short stature can occur in individuals with different genetic conditions or even in the general population without any health issues.