Significance of a new type of human fetal hemoglobin carrying a replacement isoleucine replaced by threonine at position 75 )E 19) of the gamma chain.
A new type of hemoglobin F, in which isoleucine in position 75 (E 19) of the gamma chain is replaced by a threonine residue, has been found in 29 out of 32 homozygotes for beta thalassemia. The amount of this hemoglobin ranges from traces to 40% of the total Hb F. The same gamma75 Thr chain is also present in the Hb F of 40% of normal newborns and premature infants examined, of one 14-week-old fetus and in one out of 3 patients with aplastic anemia and raised levels of Hb F. Our results strongly suggest that the synthesis of this new chain is under the control of a gamma gene nonallelic with those coding for Agamma and Ggamma chains.
D000328:Adult; D000595:Amino Acid Sequence; D000741:Anemia, Aplastic / Q000097:blood / Q000235:genetics; D002648:Child; D005312:Fetal Blood / Q000032:analysis; D005319:Fetal Hemoglobin; D005796:Genes; D006455:Hemoglobins, Abnormal; D006720:Homozygote; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases; D007532:Isoleucine; D010375:Pedigree; D013789:Thalassemia / Q000097:blood / Q000235:genetics; D013912:Threonine
D006455:Hemoglobins, Abnormal; D007532:Isoleucine; D013912:Threonine; D005319:Fetal Hemoglobin