X and Y chromosomes determine our sex. Whereas normally, girls have two X chromosomes, and boys one X and one Y, around 1 in 500 boys are born with an extra X or Y. This affects the formation of mature sperm and causes infertility.
Scientists at the Francis Crick Institute were successful in removing the extra sex chromosome and produce fertile offspring in male mice. This has the potential to bring about new possibilities in addressing this genetic cause of human infertility. Nonetheless, far more research is required before this can be transferred for use in humans.
Read more about this find in this ScienceDaily article: