On balance I would go along with DNA banking. By choice I have no children so this is theoretical for me.

One thing to bear in mind is that it is very complicated. With the exception of (relatively very rare) single-gene diseases, genetic variants are just risk factors.

For example allele 23 of gene A may code for a form of a protein which is a risk factor for disease X. That risk can be made worse for somebody who has inherited allele 76 of gene B but better if they have inherited allele 41 of gene C, and so on. The different combinations grow very rapidly.

The other very important idea to remember is that genetic risk factors (different forms of a protein encoded by different alleles of a gene) can generally always be modified (for better or worse) by environmental effects - changes in diet, other life-style changes, sometimes but not always different medications, etc.

We have a lot to learn about this but at the moment genetic determinism (OMG, it is in my genes - I am doomed.) is, in my opinion, not a helpful concept.