Which syndrome is associated with a distinct facial appearance and is a result of a chromosomal defect?

Down Syndrome is associated with a distinct facial appearance and results from a chromosomal defect, specifically an extra copy of chromosome 21, which is commonly referred to as Trisomy 21. Individuals with Down Syndrome often exhibit characteristic physical features, such as a flat facial profile, slanted eyes, and a short neck, all of which are directly linked to the presence of this extra genetic material.

In contrast, the other conditions listed do not have a specific chromosomal basis or recognizable facial features. Cerebral Palsy is primarily a motor function disorder caused by brain damage, Autism relates to a spectrum of developmental disorders affecting social skills and behavior without unique physical characteristics, and Intellectual Disability encompasses a wide range of cognitive impairments that may not manifest in distinct facial features. Therefore, Down Syndrome stands out due to its clear association with both a chromosomal defect and its identifiable physical traits.