<unk>  can be caused by mutations in the β globin gene cluster, or the γ gene promoter region. In addition HbF levels are influenced by polymorphisms in the BCL11A gene and in the MYB gene enhancer. In<unk>  the percentage of HbF varies from 0.8-1.0% to about 30% of the total hemoglobin, but levels as high as 100% can be seen in homozygotes for delta beta thalassemia.
Hereditary persistence of fetal hemoglobin
Paroxysmal nocturnal hemoglobinuria
Paroxysmal cold hemoglobinuria
Beta thalassemia
Neonatal alloimmune thrombocytopenia
Congenital hemolytic anemia
Gestational thrombocytopenia
Hemoglobin Lepore syndrome