Menopause
Menopause typically occurs between 49 and 52 years of age. The majority of women have their last period between the ages of 48 and 55. The average age of the last period in the United States is 51 years, in the United Kingdom is 52 years, in Ireland is 50 years and in Australia is 51 years. In India and the Philippines, the median age of natural menopause is considerably earlier, at 44 years. The menopausal transition or perimenopause leading up to menopause usually lasts 7 years (sometimes as long as 14 years).
Advanced maternal age
Women with an inherited mutation in the DNA repair gene "BRCA1" undergo menopause prematurely, suggesting that naturally occurring DNA damages in oocytes are repaired less efficiently in these women, and this inefficiency leads to early reproductive failure. Genomic data from about 70,000 women were analyzed to identify protein-coding variation associated with age at natural menopause. Pathway analyses identified a major association with DNA damage response genes, particularly those expressed during meiosis and including a common coding variant in the "BRCA1" gene.