<qa>  What is the cause of POF?Premature ovarian failure POF affects approximately 1 of women. For most women a cause is not found, but structural abnormalities of the X-chromosome commonly lead to POF, suggesting genes on the X-chromosome are necessary for normal ovarian function. It is known that certain gene mutations on the X-chromosome can lead to changes in the normal random pattern of X-chromosome inactivation in females. 