Ordering Recommendation

Supports a clinical diagnosis of Alzheimer disease (AD) in symptomatic individuals. Use for AD risk assessment only. Genetic counseling and informed consent are strongly recommended prior to ordering and post test to discuss results.


Polymerase Chain Reaction/Fluorescence Monitoring


Mon, Thu


2-7 days

New York DOH Approval Status

This test is New York DOH approved.

Specimen Required

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

Plasma or serum. Heparinized specimens. Frozen specimens in glass collection tubes.


Testing of fetal specimens or specimens from patients under the age of 18 years is not offered.


Ambient: 72 hours; Refrigerated: 1 week; Frozen: 1 month.

Reference Interval

Homozygous apo e3 (e3/e3): This genotype is the most common (normal) genotype.

Interpretive Data

Background Information for Apolipoprotein E (APOE) Genotyping, Alzheimer Disease Risk
Alzheimer disease (AD), the most common cause of dementia, is characterized by progressive cognitive decline including memory, problem-solving skills, multi-step tasks, planning, and changes in personality. A clinical diagnosis of probable AD can be made based on clinical signs and neuroimaging, and the diagnosis is confirmed postmortem based on neuropathologic findings. The e4 allele of the APOE gene has been widely demonstrated to be associated with increased risk of AD. In individuals with a clinical diagnosis of AD, the presence of the e4 allele increases the likelihood that the diagnosis is correct, but is not diagnostic alone. APOE genotyping is not recommended for predicting AD risk in asymptomatic individuals.
Prevalence of APOE e4: Heterozygosity and homozygosity for the e4 allele is present in approximately 25 percent and 1-2 percent of the general population, respectively.
Inheritance of APOE e4: Semi-dominant.
Penetrance of APOE e4:
Incomplete and influenced by age, gender, ethnicity, family history and environmental factors. The e4 allele is neither necessary nor sufficient for diagnosing AD; therefore, not all individuals with AD have the e4 allele and not all individuals with the e4 allele will develop AD.
Cause: Multi-factorial. 
Variants Tested:
Two single nucleotide polymorphisms in the APOE gene at codons 130 (rs429358) and 176 (rs7412). The e3 allele (Cysteine at 130 and Arginine at 176) is the most common in the general population. The e4 allele (Arginine at 130 and 176) is associated with increased AD risk. The e2 allele (Cysteine at codons 130 and 176) may be associated with a lower risk for AD but homozygosity has been associated with increased risk for type III hyperlipoproteinemia.
Clinical Sensitivity: Approximately 30-60 percent of individuals diagnosed with AD carry at least one e4 allele. The e4/e4 genotype is found in approximately 13 percent of the AD population and 20 percent of the familial AD population.
Methodology: Polymerase chain reaction (PCR) and fluorescence monitoring.
Analytical Sensitivity and Specificity:
99 percent.
Only the APOE alleles e2, e3 and e4 will be detected; rare alleles are not detected by this test. Diagnostic errors can occur due to rare sequence variations.

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Compliance Category

Laboratory Developed Test (LDT)


Hotline History


CPT Codes



Component Test Code* Component Chart Name LOINC
2013338 APOE Specimen 31208-2
2013342 APOE Alzheimer Disease Risk, Genotype 42315-2
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • Alzheimer's
  • Alzheimers
  • APOE
  • ApoE 2 mutations
  • ApoE Alzheimer Risk
  • ApoLipoprotein E Genotype
Apolipoprotein E (APOE) Genotyping, Alzheimer Disease Risk