Is there a reason for BRCA?

Conditional loss of Brca1 in oocytes causes reduced litter size, ovarian reserve depletion and impaired oocyte in vitro maturation with advanced reproductive age in mice

https://tinyurl.com/5cdrru74

Darwin’s theory of evolution includes the concept that a mutation persists because of biological advantage. Meaning that there must be some benefit for women who carry the BRCA mutation.

This fundamental research, using mice who have BRCA knockout (mutation), looked at the fertility and fecundity for these mice compared to non BRCA affected mice. No change in fertility was observed with normal follicle production and fertile lifespan.

However, the size of the litter with fewer infant mice was shown to be significantly smaller for mice which are BRCA positive.

This finding suggests a possible advantage, fewer offspring may mean better maternal care and more likely survival.