Hemophilia A subjects with an intron-22 gene inversion mutation show CD4+ T-effector responses to multiple epitopes in FVIII
BackgroundAlmost half of severe hemophilia A (HA) is caused by an intron 22 inversion mutation (Int22Inv), which disrupts the 26-exon F8 gene.Inverted F8 mRNA exons 1-22 are transcribed, while F8B mRNA, containing F8 exons 23-26, is transcribed from a promoter within intron 22.Neither FVIII activity nor FVIII antigen (cross-reacting material, CRM)