alpha thalassemia

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α thal·as·se·mi·a

thalassemia due to one of two or more genes that depress (severely or moderately) synthesis of α-globin chains by the chromosome with the abnormal gene. Heterozygous state: severe type, thalassemia minor with 5-15% of Hb Bart at birth, only traces of Hb Bart in adult; mild type, 1-2% of Hb Bart at birth, not detectable in adult. Homozygous state: severe type, erythroblastosis fetalis and fetal death, only Hb Bart and Hb H present; mild type not clinically defined.
See also: hemoglobin H.
References in periodicals archive ?
The traits, such as sickle trait (AS), beta thalassemia trait, and alpha thalassemia trait, are particularly important in the prenatal patient, where it is vital to understand the likelihood of severe versus mild disease.
In addition, beta thalassemia and alpha thalassemia are very prevalent in the population.
Notably, there are two genetic forms of alpha thalassemia minor (severe).
8) The most common alpha thalassemia mutation, occurring in more than 1% of individuals of sub-Saharan ancestry, is known as alpha 3.