fetal hemoglobin

hemoglobin /he·mo·glo·bin/ (he´mo-glo″bin) the oxygen-carrying pigment of erythrocytes, formed by developing erythrocytes in the bone marrow; a hemoprotein made up of four different polypeptide globin chains that contain between 141 and 146 amino acids. Hemoglobin A is normal adult hemoglobin and hemoglobin F is fetal hemoglobin. Many abnormal hemoglobins have been reported; the first were given capital letters such as hemoglobin E, H, M, and S, and later ones have been named for the place of discovery. Homozygosity for hemoglobin S results in sickle cell anemia, heterozygosity in sickle cell trait. Symbol Hb.

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fetal hemoglobin  that forming more than half of the hemoglobin of the fetus, present in minimal amounts in adults and abnormally elevated in certain blood disorders.

mean corpuscular hemoglobin  (MCH) the average hemoglobin content of an erythrocyte.

muscle hemoglobin  myoglobin.

reduced hemoglobin  that not combined with oxygen.

hemoglobin S  the most common abnormal hemoglobin, with valine substituted for glutamic acid at position six of the beta chain, resulting in the abnormal erythrocytes called sickle cells, and causing sickle cell anemia.

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fetal hemoglobin

n.

The predominant form of hemoglobin in a fetus and a newborn. Normally present in small amounts in an adult, it may be abnormally elevated in certain forms of anemia. Also called Hemoglobin F.

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fetal hemoglobin,

hemoglobin F, the major hemoglobin present in the blood of a fetus and neonate. Hemoglobin F is present in only trace amounts in the blood of normal adults.

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fetal hemoglobin

Hemoglobin F An immature Hb composed of 2 α and 2 γ chains that usually disappears in the neonatal period. See Hereditary persistence of fetal hemoglobin.