Depends on whether it’s a recessive or dominant gene (and some other things too), but this was far enough back and distant enough that it is unlikely to have affected Ms. Presley.
Her lifestyle would have greatly affected her longevity though.
I have several very rare genetic variants that have never been seen before and were reported to the database as likely pathogenic and one reported as uncertain significance.
If I married a cousin with them my kid would be more prone to getting whacked with it than if I had kids with person who didnt have them. Since they are so rare, child would have a better chance with a non relative.
Elvis had a lot wrong with him that could have been genetic and passed on...that got exacerbated by the environment.
Science is still a long way off from understanding the genetic role in most diseases.
I am in two research studies based on my genes. So many variables that have a bearing on disease.