期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1976
卷号：73
期号：10
页码：3633-3636
DOI：10.1073/pnas.73.10.3633
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The extent of variability in the number of human hemoglobin (Hb) alpha chain loci has not yet been conclusively determined. There is evidence that in some populations individuals may possess two alpha-chain loci, while in other populations only one locus is present. Electrophoresis of peripheral blood from 53 heterozygotes for Hb G Philadelphia (alpha 68 Asn leads to Lys) revealed that the proportion of Hb G is trimodally distributed, with modes at approximately 20, 30, and 40% Hb G. Familial, hematologic, and statistical studies suggest that hte proportion of Hb G is not random but is genetically controlled and inversely correlated with mean cell volume. Two alternative genetic models are proposed to explain these findings: one assums alpha-thalassemia, while the other postulates variability in the number of alpha-chain loci in the American Black population. Biosynthetic studies of blood from 15 subjects revealed balanced synthesis of alpha and beta globin chains in heterozygotes from all three classes, strongly supporting variable gene dosage rather than alpha-thalassemia as the mechanism underlying the observed trimodality in the proportion of Hb G. Incompatibilities between out results and current concepts of alpha-thalassemia are discussed in the context of differences between Black compared with Oriental and Italian forms of Hb H disease.
