Britain made history this week by becoming the first country to introduce a “3-parent baby” bill.

Approved by the House of Commons, the Human Fertilization and Embryology (Mitochondrial Donation) Regulations 2015 seeks to eradicate genetic diseases that are passed from mother to child via defective mitochondria. (Defective mitochondria causes diseases such as brain damage, heart failure and blindness.) The genetic diseases would then cease to be passed to future generations.

For those who aren’t up on their fifth-grade science, here’s how it works: There are two healthy parents, save for the defective mitochondria (the cells that convert food into energy). A third woman would donate her healthy mitochondria via a modified in-vitro fertilization (IVF) technique. From then on, the mitochondria are permanently altered for the better.

There are two ways the procedure can be executed. For visual learners, diagrams are below:

In the first method, the nuclei from the parents’ fertilized embryo is added to the donor’s fertilized embryo. The modified embryo is then placed into the womb.

In the second method, the nucleus from the mother’s egg is placed into the donor egg, with the healthy mitochondria.

In fact, calling a resulting baby from the procedure a “3-parent baby” is a misnomer: The donor would only give about .1% of her DNA. It would only change the portion that houses the genetic disease. Per the BBC, reproductive ethicist Dr. Gillian Lockwood notes:

Less than a tenth of one per cent of the genome is actually going to be affected. It is not part of what makes us genetically who we are. It doesn’t affect height, eye colour, intelligence, musicality.

If the measure passes through the House of Lords, the first baby to benefit from this procedure could be born next year.

NPR notes that U.S. agencies, such as the Food and Drug Administration (FDA) have also been looking into the process, since 1-4K American children are born with a mitochondrial disease (numbers per the United Mitochondrial Disease Foundation).

It’s safe to say that Britain will pave the way with how they handle this measure, and the world will be watching (and learning).