Lab Test

Apo E Genotyping for Cardiovascular Disease Risk

Apolipoprotein E Genotyping, cardiovascular disease, hyperlipidemia

Test Codes

EPIC: LAB6375, Code: GAPOG

Department

Molecular Pathology

Instructions

This test is available to outpatients only and should only be ordered once in a lifetime.

For questions, please call 800-551-0488.

Specimen Collection Criteria

Collect: One 10 mL whole blood in Lavender-top EDTA tube. (Minimum: 5.0 mL)

Physician Office/Draw Specimen Preparation

Do not freeze specimens. Maintain whole blood at room temperature (20-26°C or 68-78.8°F) prior to transport.

Preparation for Courier Transport

Transport: Whole blood at room temperature (20-26°C or 68-78.8°F). (Minimum: 5.0 mL whole blood)

Rejection Criteria

  • Frozen specimens. 
  • Unlabeled tubes. 
  • Specimens collected in heparin (Green-top), clot tubes (Red-top), or SST tubes.
  • This test will only be performed once in a lifetime for a patient.

In-Lab Processing

Do not freeze specimens. Maintain specimen refrigerated (2-8°C or 36-46°F) prior to testing.

Storage

Specimen Stability for Testing:

Whole Blood
Room Temperature (20-26°C or 68-78.8°F): 72 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): Unacceptable

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days

Extracted DNA may be available for additional testing if clinically indicated. Contact the Molecular Pathology Laboratory for verification.

Laboratory

Royal Oak Clinical Molecular Pathology Laboratory

Performed

Once per week.
Results available in 7-10 business days.

Reference Range

Wild type; e3/e3 genotype.

Test Methodology

Real-Time Polymerase Chain Reaction (PCR) with Allelic Discrimination.

Interpretation

  • Genetic variation of the Apo E locus is an important determinant of plasma lipid levels and relative risk of atherosclerosis.
  • The Apo E gene is present in three common allelic forms: e2, e3 ande4. The e3 allele is the most common allele in all populations studied to date. The e4 allele is associated with increased plasma cholesterol levels and increased susceptibility to cardiovascular disease, particularly in the e4/e4 homozygotes. The e2 allele is associated with hyperlipidemia; most patients with type III hyperlipoproteinemia are homozygous e2/e2.

Clinical Utility

  • Detection of Apo E alleles e4 and e2 is associated with increased risk of cardiovascular disease.
  • This test is not available for Alzheimer's disease testing.
  • Testing for Apo E Genotyping is recommended for:
    • Assessment of cardiovascular disease risk in patients with hyperlipidemia/dyslipidemia.
    • Assessment of cardiovascular disease risk in patients with positive family history of atherosclerotic (coronary artery, cerebrovascular, or peripheral vascular) disease.
    • Patients who are first-degree relatives of family members with known Apo E variant alleles e2 and e4.

CPT Codes

81401

Contacts

Last Updated

10/3/2022

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