For 10 points, name this genetic disorder in which individuals possess an extra copy of chromosome 21.
Jerome Lejeune first discovered the cause of this disease. Common characteristics associated with sufferers of this disease include epicanthic eye folds; a broad, flat face; and a wrinkled tongue; in addition to mental impairment. This disease, which was formerly known as mongolism, is significantly more common in children born to mothers over the age of 40. For 10 points, name this genetic disorder in which individuals possess an extra copy of chromosome 21.
Jerome Lejeune first discovered the cause of this disease. Common characteristics associated with sufferers of this disease include epicanthic eye folds; a broad, flat face; and a wrinkled tongue; in addition to mental impairment.
{Down} syndrome [accept {trisomy 21} before "{21}" is read]