Globin chain synthesis in the greek type (A gamma) of hereditary persisitence of fetal haemoglobin.
Globin chain synthesis was studied in a family with both the Greek (Agamma) type of hereditary persistence of fetal haemoglobin and beta thalassaemia. The ratio of alpha/(gamma+beta+delta) chain synthesis in the hereditary persistence of fetal haemoglobin (HPFH) heterozygotes was 0.97 while in the HPFH/beta-thalassaemia heterozygote it was 2.14. However, calculation of the amounts of haemoglobin synthesized per cell suggests that in the HPFH/beta-thalassaemia heterozygote, the beta- and Agamma-chain genes in cis to the HPFH determinant are unable to compensate for the deficiency of chains imposed by the beta-thalassaemia gene in trans and that the increased synthesis of Hb F is directed by the gamma-chain genes located on the beta-thalassaemia chromosome. The data suggest that synthesis of beta and Agamma chains in the Greek HPFH is fixed at a 'preset' level and indicate that the defect might be due to an abnormality in the rate of transcription of the closely linked beta-, delta- and gamma-chain genes.
D000375:Aging; D000596:Amino Acids / Q000032:analysis; D005260:Female; D005319:Fetal Hemoglobin / Q000032:analysis; D014644:Genetic Variation; D005914:Globins / Q000032:analysis / Q000096:biosynthesis*; D006115:Greece / Q000208:ethnology; D006455:Hemoglobins, Abnormal / Q000032:analysis; D006579:Heterozygote; D006801:Humans; D008875:Middle Aged; D010375:Pedigree; D013789:Thalassemia / Q000097:blood*
D000596:Amino Acids; D006455:Hemoglobins, Abnormal; D005914:Globins; D005319:Fetal Hemoglobin