I've a cat I took responsibility for a year ago. He is now 2 years old. He was 'fixed' before I got him. He was never declawed. He is usually REALLY good about not scratching furniture or things he shouldn't. Until Saturday morning. I left my closet open a crack, and he is a curious fellow, and loves the closet for some reason.
Defects in the chromosomes can cause premature menopause. For example, women with Turner's syndrome are born without a second X chromosome or without part of the chromosome. The ovaries don't form normally, and early menopause is often the result.
1 Changes in the levels of these two hormones happen when the ovaries, for unknown reasons, prematurely stop releasing eggs. When this happens before the age of 40, it's called premature ovarian failure. Unlike premature menopause, premature ovarian failure is not always permanent.  Induced menopause.