- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 1 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Characteristics: Hyperlipoproteinemia III (HPL III) is characterized by increased cholesterol and triglyceride levels, presence of B-VLDL, xanthomas, and premature vascular disease including coronary heart disease (CHD) and peripheral artery disease.
Incidence of HPL III: Approximately 1 in 5,000.
Inheritance: Autosomal recessive.
Penetrance: 1 to 5 percent of individuals homozygous for the E2 allele and 26 percent of those heterozygous for both E2 and familial hypercholesterolemia will develop symptoms.
Cause: The E2 isoform binds the lipoprotein receptors with only 2 percent of the affinity of E3 and E4 resulting in impaired clearance of chylomicron and VLDL remnants and increased plasma cholesterol and triglyceride levels.
Mutations Tested: E2, E3 (normal) and E4 alleles of the apolipoprotein E gene.
Clinical Sensitivity: About 5 percent of individuals with premature CHD are homozygous for E2.
Methodology: Polymerase chain reaction (PCR) and fluorescence monitoring using hybridization probes.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Rare isoforms of APOE will not be detected. If rare alleles are suspected, phenotyping by isoelectric focusing may be indicated. Diagnostic errors can occur due to rare sequence variations.
This test is performed pursuant to an agreement with Roche Molecular Systems, Inc.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
This test is not recommended for nonsymptomatic patients under 18 years of age.
|Component Test Code*||Component Chart Name||LOINC|
|0055566||Apo E for Cardiovascular Risk||21619-2|
|2001298||APO E Specimen||31208-2|
- ApoE cardiac risk
- APO E Cardiac Risk
- ApoE 2 mutations
- ApoLipoprotein E Genotype