GAMMA-CHAIN ABNORMALITIES AND GAMMA-GLOBIN GENE REARRANGEMENTS IN NEWBORN BABIES OF VARIOUS POPULATIONS

The present review provides a summary of quantitative hemoglobin data and lists the results of gene mapping and sequencing analyses for blood samples from newborn babies of different countries. Methodology suitable for such studies is reviewed, various abnormal fetal hemoglobins are discussed, the occurrence of Hb Bart's (gamma-4) and of the embryonic zeta-chain is evaluated, and the various types of gamma-globin gene rearrangements (-A-gamma.A-gamma-; -G-gamma.G-gamma-; gamma-thalassemia; gamma-globin gene triplications, quadruplications, and quintuplications) are compared. The several tables list the frequencies of the common A-gamma-T variant and of the different gamma-gene rearrangements in various populations, while the results of quantitative analyses suggest that most anomalies are not associated with disease.