hemoglobin F (hereditary persistence of)

he·mo·glo·bin F (he·red·i·tar·y per·sis·tence of)

[MIM*142200.0026-]
a condition due to an allele that depresses synthesis of β and δ chains (as in thalassemia), but this is fully compensated by increased γ chain synthesis and there is no anemia; there are 3 types: African type, no β or δ chain synthesis by the chromosome with the abnormal gene, heterozygotes have 20-30% Hb F and Hb A2 slightly decreased, homozygotes form no Hb A or Hb A2; Greek type, reduced β and δ chain synthesis, heterozygotes have 10-20% Hb F and normal Hb A2; Swiss type, heterozygotes have only 1 to 3% Hb F and normal Hb A2.