There is also a combined variant, HbSC (known as sickle-hemoglobin C disease), or double heterozygote
. Mongia et al.
The case presented in this issue of Clinical Chemistry demonstrates the remarkable effect of double heterozygosity for Hb S and Hb [O.sub.Arab] on the clinical severity of the disease, compared with the more frequently observed Hb S/C double heterozygote
. The worse effect of Hb [O.sub.Arab] has been attributed to enhanced polymerization of Hb S and to the accompanying dehydration of erythrocytes imposed by the presence of the positively charged Hb [O.sub.Arab] variant.
Mean [P.sub.i] levels in the double heterozygote
class of our Boggs-RR x CX1834-1-2 population (equivalent to the [F.sub.1]s in the population of Oltmans et al., 2004) were only marginally greater than those of the individuals homozygous for Boggs-RR alleles at the LG L and N marker loci.
The last indeterminate sample had an unexpectedly low temperature transition and sequenced as the double heterozygote
1298AC, 1317TC (Fig.
The most common form of dominance-by-dominance epistasis (12/17) is for the double heterozygote
to be underdominant or weigh less than predicted by additivity.
The GMF of the double heterozygote
can be higher than that of the homozygote (i,i) but not more than by a multiplier [(1 - r).sup.p].
Subsequent sequencing revealed a double heterozygote
, HBB c.[9C[right arrow]T; 20A[right arrow]T].
With linkage, the double heterozygote
, AaBb, is special because the cis- and trans- forms are distinct.
The double heterozygote
shows the greatest deviation from wild type because 2 mismatches are present within the PCR product.
The double heterozygote
of two endothelin-1 gene polymorphisms (G8002A and -3A/-4A) is related to big endothelin levels in chronic heart failure.
HPLC detected all of the diseases detected by IEF except for one double heterozygote
, in which the printed chromatogram was entirely normal (Table 2).
The genetic pathogenesis mainly involves three different gene alterations; they can be homozygotes, compound heterozygotes or double heterozygotes
. Homozygotes and compound heterozygotes have a structural variant of self-association sites, while as in double heterozygotes
, one spectrin allele caries a structural defect and the second defect located trans to the structural variant produces a thalassemia like defect resulting in low erythrocyte spectrin.