Apolipoprotein (apo) E is a protein component of lipoproteins, 50% of which resides in HDL, 10% in LDL, 20% in IDL, and 20% in VLDL cholesterol fractions (1). Apo E binds to the LDL receptor, also termed the B,E receptor, because the receptor accepts both apo B and apo E. Apo E is also thought to bind to a specific chylomicron remnant receptor by virtue of its structural determinants. The heterogeneity in receptor binding of different varieties of apo E is explained by the affinity of different apo E alleles to various receptors. Apo E polymorphisms may be explained by three major alleles: apo Ee2, apo Ee3, and apo Ee4, which are found in 10%, 76%, and 13%, respectively, of the Caucasian population (2). The polymorphisms are due to substitution of a cysteine for an arginine at residue 112 or 158, or at both residues. The apo Ee2 variant has the lowest affinity for the LDL receptor. There is an LDL concentration gradient in both the healthy population and in those with coronary heart disease. Individuals homozygous for apo Ee2 have the lowest concentrations of LDL, and apo Ee4 homozygotes have the highest LDL concentrations (3). The apo Ee4 allele has also been associated with Alzheimer disease. However, the mechanisms of this association are not yet clear (4). Thus, the interest in apo E polymorphisms is high, both on the basis of epidemiological research and for the purpose of clarifying individual lipid disturbances or dementias. We have successfully applied the oligonucleotide ligation assay (OLA) technique to screen for mutations causing familial hypercholesterolemia (5). We have now adapted this technique for the detection of apo E polymorphisms in large numbers of samples.
PCR amplification of genomic DNA from peripheral blood was performed in a Perkin-Elmer 9600 Thermocycler. A 310-bp fragment of …
[1]
F. Luft,et al.
Oligonucleotide ligation assay (OLA) for the diagnosis of familial hypercholesterolemia
,
1996,
Nature Biotechnology.
[2]
W. März,et al.
Apolipoprotein E Polymorphism Is Associated with Both Senile Plaque Load and Alzheimer‐Type Neurofibrillary Tangle Formation a
,
1996,
Annals of the New York Academy of Sciences.
[3]
K. Livak,et al.
Oligonucleotides with fluorescent dyes at opposite ends provide a quenched probe system useful for detecting PCR product and nucleic acid hybridization.
,
1995,
PCR methods and applications.
[4]
E. Winn-Deen,et al.
High-density multiplex detection of nucleic acid sequences: oligonucleotide ligation assay and sequence-coded separation.
,
1994,
Nucleic acids research.
[5]
R Higuchi,et al.
Chelex 100 as a medium for simple extraction of DNA for PCR-based typing from forensic material.
,
2013,
BioTechniques.
[6]
A. Schepartz,et al.
Polyether tethered oligonucleotide probes
,
1991
.
[7]
F. Barany.
Genetic disease detection and DNA amplification using cloned thermostable ligase.
,
1991,
Proceedings of the National Academy of Sciences of the United States of America.
[8]
M. King,et al.
Atherogenic lipoprotein phenotype. A proposed genetic marker for coronary heart disease risk.
,
1990,
Circulation.
[9]
G. Assmann,et al.
Apolipoprotein E polymorphism and hyperlipidemia.
,
1984,
Clinical chemistry.