QUANTITATION OF 3 TYPES OF GAMMA-CHAIN OF HBF BY HIGH-PRESSURE LIQUID-CHROMATOGRAPHY - APPLICATION OF THIS METHOD TO THE HBF OF PATIENTS WITH SICKLE-CELL-ANEMIA OR THE S-HPFH CONDITION

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  • 1 January 1981
    • journal article
    • research article
    • Vol. 57  (1) , 75-82
Abstract
A modification of a high pressure liquid chromatographic (HPLC) procedure is described that enables the complete separation and quantitation of the A.gamma.T, A.gamma.I and G.gamma. chains in human fetal Hb. The method, which is fast and accurate, requires 5-2000 .mu.g Hb F. Hb F purity is not essential and admixture of up to 70% adult Hb does not interfere with the determination. The method was applied to the Hb F of 64 Black SS [homozygous sickle cell gene] patients and 7 persons with the Hb S-HPFH (G.gamma.A.gamma. type) condition. Both adult G.gamma. to A.gamma. (2:3) and newborn G.gamma. to A.gamma. (3:2) ratios were observed in adult SS patients, 8 yr and older. Only 12% of the SS patients had the newborn ratio. This high G.gamma. to A.gamma. ratio may be due to a modification of the genetic switch mechanism that regulates the change of this ratio after birth. Intermediate G.gamma. to A.gamma. ratios were only found in young SS patients, 5 yr of age or less. The results suggest a delayed switch of the newborn .fwdarw. adult ratio in sickle cell anemia. The A.gamma.T chain was present in only 6% of all SS patients. One patient is homozygous for this variant chain. Of the 7 subjects with Hb S-HPFH 3 were positive for the A.gamma.T chain. Its percentage was low, which suggests that the A.gamma.T chain gene is in trans of the HPFH determinant. Quantitation of the 3 .gamma. chain types is also possible in the Hb F from Hb S heterozygotes with (nearly) normal Hb F levels. Such an analysis is useful for an evaluation of genetic conditions involving variations in the production of (different types of) Hb F.