hemoglobinopathy

A disorder or disease caused by or associated with the presence of abnormal hemoglobins in the blood, e.g., sickle cell disease, hemoglobin C, D, E, H, or I disorders. Occasionally, combinations of abnormal hemoglobins are seen in hemoglobinopathies. [hemoglobin + G. pathos, disease]

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he·mo·glo·bin·op·a·thy or chiefly Brit hae·mo·glo·bin·op·a·thy .hē-mə-.glō-bə-'näp-ə-thē n, pl -thies a blood disorder (as sickle-cell anemia) caused by a genetically determined change in the molecular structure of hemoglobin

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he·mo·glo·bin·op·a·thy (he″mo-glo″bin-opґə-the) [hemoglobin + -pathy] 1. any inherited disorder caused by abnormalities of hemoglobin, resulting in conditions such as sickle cell anemia, hemolytic anemia, or thalassemia. 2. sometimes more specifically, a hemoglobin disorder involving a variation or variations of a globin chain such as changes or substitutions in the amino acid sequences, or moving of a chain from its usual place in the molecule. (In this case hemoglobinopathies are distinguished from thalassemias, which involve reduced or absent synthesis of normal polypeptide chains.) When the site of an aberration is known, the abnormality of the peptide chain, the number of the altered amino acid, and the nature of the replacement are indicated. For example, hemoglobin S is expressed as α₂^Aβ₂^S, or α₂^Aβ₂^{6 valine}, and hemoglobin G_Philadelphia is expressed as α₂^Gβ₂^A, or α₂^{6 lysine}β₂^A. If more than one hemoglobin is present, the phenotype is designated by listing them in order of decreasing concentrations; for example, the phenotype for sickle cell trait is expressed as AS, for sickle cell anemia as SS, and for sickle cell–hemoglobin C disease as SC.