Elevated G gamma:A gamma globin chain ratio in homozygous beta thalassemia.
G gamma:A gamma chain ratios were determined in homozygous beta thalassemia and cord blood samples using triton-urea polyacrylamide gel electrophoresis. The mean G gamma/G gamma + A gamma proportion in the two groups were 0.62 +/- 0.10 and 0.72 +/- 0.03, respectively. There was no significant correlation of the gamma chain composition in either fetal hemoglobin or total hemoglobin levels; this suggests that these two factors do not influence gamma chain ratios. There was also no marked variation in the G gamma:A gamma ratios in beta thalassemia patients when they were divided into higher fetal hemoglobin (greater than 50%) and lower fetal hemoglobin (less than 50%) groups. These observations are consistent with the finding of a selective advantage of G gamma chains over A gamma chains in disorders where the erythropoietic stress is higher than normal, and may be inherited as a specific genetic entity in haplotypic polymorphism.
Ponnazhagan
S
S
Department of Genetics, P.G. Institute of Basic Medical Sciences, University of Madras, Taramani, India.
Betsy
J
J
Sarkar
R
R
D005312:Fetal Blood / Q000378:metabolism; D005319:Fetal Hemoglobin / Q000737:chemistry / Q000235:genetics*; D005914:Globins / Q000378:metabolism*; D006720:Homozygote; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D013789:Thalassemia / Q000097:blood* / Q000235:genetics
D005914:Globins; D005319:Fetal Hemoglobin