First-generation assay epitopes typically span amino acids 4 to 10 of the Hb [beta] chain, (7) encompassing the altered amino acid at position 6 present in Hb S
and Hb C variants.
(14) For persons affected by conditions proven to shorten RBC survival such as Hb S
, C, or D disease, the use of alternate tests are recommended to estimate a patient's past average glycemia.
This analysis identified a substitution at codon 6 [GAG to GTG (Glu to Val)] on one allele, corresponding to Hb S
, and a substitution at codon 1 [GTG to GCG (Val to Ala)] on the other allele, corresponding to Hb Raleigh.
Hb D-Los Angeles associated with Hb S
or [beta]-thalassemia in four Mexican Mestizo families.
With alkaline agarose gel testing, some common Hb variants comigrate, such as Hb C, Hb E, Hb A2 & Hb O-Arab and Hb S
, Hb D and Hb G.
SCD is diagnosed by the measurement of substantial amounts of Hb S
by at least 2 separation methods, including HPLC and an electrophoretic method, such as IEF, cellulose acetate, or citrate agar.
The presence of Hb S
trait produced statistically significant differences for all methods except for the D-10 and PDQ methods.
For specimens that showed chromatogram patterns consistent with sickle trait, the presence of Hb S
was confirmed by use of the sodium metabisulfite reduction test (20).
Overestimation of gHb by the HA8140 ion-exchange method with samples containing Hb S
trait was clinically significant only at 6% Hb [A.sub.1c].
The Hb migration order of IEF is the same as that of alkaline electrophoresis with resolution of Hb C from Hb E and Hb O and Hb S
from Hb D and Hb G.
Previous studies have shown that some gHb methods yield inaccurate results with samples heterozygous for hemoglobin (Hb) C or Hb S
Samples with hemoglobin variants were identified by comparison of retention times on the Diamat system (Bio-Rad Clinical Laboratories) to known retention times for Hb S
and Hb C.