I believe being homozygous for the delta32 mutation at the CCR5 gene locus is a possible example about which you ask. https://en.wikipedia.org/wiki/CCR5 https:

I believe being homozygous for the delta32 mutation at the CCR5 gene locus is a possible example about which you ask. https://en.wikipedia.org/wiki/CCR5 https://en.wikipedia.org/wiki/CCR5