yeah man, a little native American or Asian in the genes can kill it. I'm 1/16th native and I think I caught that trait, unfortunately.
At least I'm able to grow a goatee and mustache, which I generally wear.
But dude, when I was researching this, it did say to try just letting it grow for awhile and that it's possible that some parts will grow in well enough to cover the patchy areas, so I mean it's still worth a try I suppose.