The absence of GPI-anchored proteins in PIG-A mutated hematopoietic stem cells (HSCs) doesn't fully explain why PNH clones outperform normal HSCs.
A study of 50 PNH patients found strong associations between certain MHC alleles (specifically DRB1*15:01 and DQB1*06:02) and non-aplastic PNH outcomes.
MHC class I allele B*18:01 was linked to a higher risk of the initial severe aplastic anemia subtype, indicating that different MHC alleles influence various PNH subsets.