ABNORMAL ARRANGEMENTS IN THE ALPHA-GLOBIN AND GAMMA-GLOBIN GENE CLUSTERS IN A RELATIVELY LARGE GROUP OF JAPANESE NEWBORNS

  • 1 January 1986
    • journal article
    • research article
    • Vol. 38  (1) , 45-58
Abstract
Data were obtained on blood samples from a relatively large group (264) of healthy Japanese newborns, collected at hospitals in Tokyo, Kuranshiki, and Ube. The studies included an evaluation of anomalies in .alpha.-globin gene and .gamma.-globin gene arrangements using gene mappring and .gamma.-chain composition analyses. The results confirmed the rarity of .alpha.-thalassemia among Japanese; only a few babies had .alpha.-thalassemia-2-trait (the -3.7-kilobase [kb] detection), while others had a .alpha.-globin gene tripilications (both the .alpha..alpha..alpha.anti-3.7 and the .alpha..alpha..alpha.anti-4.2 types). Among the .gamma.-globin gene anomalies that were observed, a few babies had the -A.gamma.-A.gamma.- globin gene arrangement or the -G.gamma.A.gamma.- type of deletion. The .gamma.-chain triplication (-G.gamma.-A.gamma.-G.gamma.-A.gamma.-) occurred in 10 out of 256 newborns, and its frequency exceeded that of its corresponding -G.gamma.A.gamma.- delection by a factor of 5. The restriction endonuclease XmnI was a useful tool, in addition to the enzymes Bg1II and Bc1I, to evaluate and confirm the .gamma.-globin gene deletion and triplication. The A.gamma.T variant, which is the product of a mutant A.gamma.-globin gene, occurred at a frequency of 0.156. The chromosome carrying this mutant A.gamma. gene had a characteristic haplotype that was originally seen in black and Mediterranean patients with Hemoglobin (Hb) S or with .beta.-thalassemia.