Interesting, never heard that until now. I found this:
He appeared to suffer symptoms of the condition in his final years, including an irregular heartbeat, fatigue, fainting and high blood pressure. ......The new findings suggest that regardless of his diet, the iconic singer was always destined to die young.
---
https://www.mirror.co.uk/tv/tv-news/elvis-death-shocking-new-dna-3280460
I saw a documentary a year so ago about the genetic element. Very interesting and convincing. I had thought about LMP at the time I saw it. Sad.