What is a significant physical characteristic of individuals with down syndrome?

Individuals with Down syndrome often exhibit a range of distinct physical characteristics, and one of the most notable is the presence of slanted-appearing eyes. This feature is typically associated with the specific anatomical development patterns that accompany Down syndrome, which is caused by an extra copy of chromosome 21.

The eyes may appear different due to the shape of the eyelids, which can include an epicanthic fold—a skin fold of the upper eyelid. This fold can create the impression of slanted eyes. This characteristic is recognized as part of the syndrome and helps in identifying individuals with Down syndrome.

The other options listed, such as long limbs, a muscular build, and large head size, do not accurately describe the common physical features associated with Down syndrome. Individuals with Down syndrome typically have shorter stature, and while some may have larger heads, it is not a universally defining trait like the distinctive eye shape. Thus, the slanted-appearing eyes serve as a significant, recognizable feature of this condition.