What physical feature is commonly associated with Down syndrome?

• A. Broad forehead and slanted eyes
• B. Palm with a single simian crease
• C. Short stature and broad hands
• D. Overly flexible joints

Answer: (B)

The feature that is commonly associated with Down syndrome is the presence of a single transverse palmar crease, often referred to as a simian line. This physical trait occurs because individuals with Down syndrome have an additional copy of chromosome 21, which can affect their overall development, including the structure of their hands. The presence of this crease can be indicative of chromosomal abnormalities and is seen in approximately 50-60% of individuals with Down syndrome.

While other physical features may be associated with Down syndrome, such as a broad forehead, slanted eyes, short stature, and broad hands, the defining characteristic in the context of this question is the single simian crease on the palm. This aligns with clinical observations and practices in identifying and understanding the phenotypic presentation of individuals with Down syndrome.