What syndrome results from excessive cartilage formation at the growth plates, leading to long limbs and a tall, thin body form?

The syndrome characterized by excessive cartilage formation at the growth plates, leading to long limbs and a tall, thin body form, is Marfan's syndrome. This genetic disorder impacts connective tissue, resulting in features such as elongated limbs and fingers, as well as a tall and slender build. The excess cartilage leads to an overall increase in growth and height, which is distinctly observable in individuals with this condition.

In contrast, achondroplasia is associated with shortened limbs and a disproportionate body shape rather than tall stature. Down syndrome is a chromosomal condition that can lead to various physical traits and health challenges but does not specifically cause long limbs and a tall body type. Turner's syndrome, which affects females and results from a missing or incomplete X chromosome, leads to short stature and does not share the characteristics mentioned in the question regarding limb length and body form.