Dried Blood Spot Testing

• Cholesterol absorption from the intestine
• Uptake of triglyceride-rich lipoproteins by the liver
•  The intended use of apoE genetic testing is as an aid in the selection of optimal cholesterol lowering protocols by the healthcare provider. The genetic test identifies individuals with altered lipid transport. Depending on the apoE genotype, cholesterollowering dietary interventions are very eff ective in these individuals, so determination of the genotype allows the physician to select the most eff icacious treatment regimen for the patient for lowering low density lipoprotein cholesterol and reducing heart disease risk.

 

The APOE gene has three common alleles (E2, E3, E4) that encode for three protein isoforms (E2, E3, E4). ApoE3 is the most common form of apoE. Population frequencies for these apoE alleles are:

• E2 (15%)
• E3 (65%)
• E4 (20%)

Methodology

Real time polymerase chain reaction (PCR)

Patient Preparation

None

Preferred Specimen

1.0 mL whole blood collected in EDTA (Lavender Top)

Alternate Specimen

• Buccal swab
• Dried Blood collected on an AdvanceDx 100 card

Transport Temperature

Refrigerated (ship on frozen cold packs)

E3/E3
Most common genotype; associated with:^1-2

• Decreased uptake of cholesterol by the liver
• Lower total cholesterol and LDL-C

 

E2/E2, E2/E3
Associated with:^1-2

• Lower LDL-C levels than the common E3/E3 genotype
• Lower total cholesterol and LDL-CV

 

E4/E4, E3/E4
Associated with higher LDL-C levels than the common E3/E3 genotype. Also associated with increased:^1-2

• Cholesterol absorption in the intestine
• Uptake of intestinal cholesterol by the liver
• Total cholesterol and LDL-C