Define "properly".

At one point, we thought that simply replacing a user's IP with a unique ID was enough to anonymise.

At one point, a blur or pixelating filter on a photo was sufficient to anonymise it.

At one point, Monero transactions were considered anonymous.

There is nothing that identifies a person more precisely than their genome. It is, after all, unique to each person.

That means that by definition, anonymizing genomes is impossible. If someone tells you they will 'anonymize' your genome data, run away, they don't know what they are doing.

You can't anonymize your DNA.