Complex sentence: A significant amount of excess somatotrope secretion before puberty or before the end of new bone tissue growth can lead to gigantism, a disease that causes excess growth of body (e.g. being over 7 ft. tall) and unusually long limbs.
Split into simpler sentences: A significant amount of excess somatotrope secretion before puberty, or before the end of new bone tissue growth, can lead to gigantism. Gigantism is a disease that causes excess growth of body (e.g. being over 7 ft. tall) and unusually long limbs.