Most people have only ever heard of BRCA1 or BRCA2 in connection with familial breast cancer or because of Angelina Jolie. But what a recent study found is that the activity of BRCA1 or ATM, RAD51, and MRE11 DNA repair proteins all declined with the age of oocytes of female mice and adult women. This evidence is further supported by observations that BRCA1-null mice have impaired fertility.
One would surmise that women with mutations in the BRCA1 gene would also have a shortened window of fertility. Anyways I thought it was an interesting study that gave some mechanistic insight into why fertility decreases with age.