smoking ! did you mean stunt ! they do have medicines to slow growth for too tall people to slow and or stop their growth - i seen on TV the girl was about 8 foot or so give or take and she was real young and was growing in at a alarming rate !
The main causes of a slow growth rate are hormone deficiency and severe injuries from accidents at an early age. Other causes are brain radiation treatments for cancer and hormonal problems involving the pituitary gland.