As long as i remember from my biology class (mutation)
⇒ specific facial characteristics e.g. upward slanting eyes, small folded ears, a small mouth giving the appearance of a large tongue, a small flattened nose and a short wide neck.
⇒ poor muscle tone making them appear floppy, as babies.
⇒ a single crease that goes directly across the palm of the hand.
⇒ intellectual disability
⇒ heart defects