The prevalence of HPA-1a alloimmunization and the potential risk of FNAIT depend on both the DRB3*01:01 allele and associated DR-DQ haplotypes
Alloimmunization against human platelet antigen (HPA)-1a during pregnancy can cause foetal/neonatal alloimmune thrombocytopenia (FNAIT) and severe bleeding in the foetus or newborn and likely depends on several factors. HPA-1a alloimmunization is associated with DRB3*01:01, which is associated with several DR-DQ haplotypes. However, it is not known to what extent these haplotypes contribute to the