<qa>  What is the main cause of GH deficiency?GH deficiency not only leads to short stature and obesity, but also to osteoporosis, hyperlipidemia, depressed cardiac and renal function, as well as an overall lack of energy. It is quite possible that treatment of GH-deficient patients with PHP1a could improve any or all of the above problems. GH treatment has been FDA approved for use in both children and adults with GH deficiency. Therefore, it may be possible to provide improvement in health and overall quality of life in these patients. 