APOE Alzheimer's Disease Risk

CPT: 81401

Special Instructions

This test is not approved for use in New York state.

If you have questions, please call Consumer Genetics (CG) customer service at 336-436-7089 for assistance or email [email protected].


Expected Turnaround Time

5 - 7 days


Related Documents


Specimen Requirements


Specimen

Whole blood


Volume

Fill tube to capacity.


Minimum Volume

Fill tube to capacity.


Container

Lavender-top (EDTA) tube


Collection

Invert tube immediately eight to 10 times once tube is filled at time of collection.


Stability Requirements

Temperature

Period

Room Temperature

1 month

Refrigerated

1 month

Frozen

1 month

Freeze/Thaw Cycle

Stable x2


Causes for Rejection

Wrong specimen container; mislabeled specimen


Test Details


Use

Alzheimer's disease is a progressive neurodegenerative disorder that affects more than 6.7 million Americans ages 65 and older and is the most common form of dementia in the elderly. Signs and symptoms may include cognitive decline, memory loss, loss of problem-solving skills and personality changes. Clinical symptoms appear after 60-65 years in 95% of cases. The development of late-onset disease may be influenced by age, sex, family history, level of education, history of head trauma and other factors including cardiovascular risk factors. Approximately 15-20% of late-onset disease may be familial. The APOE gene is a known susceptibility gene for Alzheimer's disease. The APOE gene encodes apolipoprotein E, which has a role in lipid metabolism. APOE has three common alleles: E2, E3 and E4. The presence of the E4 allele increases the lifetime risk of Alzheimer's disease but is neither necessary nor sufficient for the development of Alzheimer's disease. APOE E2 may have some protective effect against development of late-onset disease.1 APOE also has a rate allele: E1 (legacy name E3r). There is insufficient evidence to assess the clinical association of APOE E1 with Alzheimer's disease.2


Limitations

APOE E2, E3 and E4 are validated for this analysis. The rare APOE E1/E1, E1/E2 and E1/E3 genotypes are reported as failed results. E2/E4 and E1/E3 genotypes cannot be distinguished by this assay. Molecular-based testing is highly accurate, but as in any laboratory test, rare errors may occur. False positive or false negative results may occur for reasons that include genetic variants, blood transfusions, bone marrow transplantation, somatic or tissue-specific mosaicism, mislabeled samples or erroneous representation of family relationships. This test was developed and its performance characteristics determined by Labcorp.


Methodology

Illumina SNP Array


Footnotes

1. Goldman JS, Hahn SE, Catania JW, et al. Genetic counseling and testing for Alzheimer disease: joint practice guidelines of the American College of Medical Genetics and the National Society of Genetic Counselors. Genet Med. 2011 Jun;13(6):597-605.21577118
2. Murrell JR, Price BM, Baiyewu O, et al. The fourth apolipoprotein E haplotype found in the Yoruba of Ibadan. Am J Med Genet B Neuropsychiatr Genet. 2006 Jun 5;141B(4):426-427.16583434

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