Growth advance and early puberty maybe because
you have a disrupted hypothalamus or pituitary which allows the break that normally exists
to come off too early. That again maybe caused because there is an abnormality, a lesion
in the pituitary. The other possibility is that there are conditions of the adrenal gland
which cause excess of hormones from the adrenal glands such as congenital adrenal hyperplasia
which can masquerade as puberty but it is not a true driven puberty. We call it a gonadotropin-independent
precocious puberty. Those are early puberty is really the most common cause of growth advance.