Apolipoprotein E

Alphabetical Test listing

Apolipoprotein E-994

  
Apolipoprotein E
  
994
  
LAB994
  
MSO
  
Alzheimer's risk
APOE
  
EDTA whole blood
  
  
5.0 mL
  
0.5 mL
Submitting the minimum volume does not allow for repeat testing
  

Lavender (EDTA), 4mL

  
ACD whole blood
  

Yellow ACD (A or B)

 

  

Yellow ACD (A or B)

  

Molecular Medicare billing request

  • Complete and submit the form to notify us of the need for Allina Health Laboratory to bill insurance for Molecular testing performed
  • All information requested is required in order for your request to be completed
  

Ambient (preferred) - 7 days

Refrigerated - 7 days

Frozen - NO

  
  • Frozen whole blood samples
  • Quantity not sufficient for analysis (QNS)
  • Improper container
  
Esoterix Coagulation Lab (301537) via LabCorp (504040): R-NX
  
Mo, We, Fr
  
5 days
  

Polymerase chain reaction (PCR) with restriction enzyme digestion and polyacrylamide gel electrophoresis

  

An interpretive report will be provided

  

This test is to detect the presence of the APOE4 variant, which is associated with increased risk of late-onset (age >60-65) Alzheimer's disease (AD). Testing may be considered for patients with dementia to supplement information from clinical and other evaluations. This test is not appropriate for children. APOE genotype results are E2/E2, E2/E3, E2/E4, E3/E3, E3,E4, or E4/E4. APOE genotyping supplies supplementary information for the clinical diagnosis of Alzheimer's disease.

Alzheimer's disease (AD) is the most common form of dementia in the elderly and currently affects more that 5 million Americans. It is a progressive neurodegenerative disorder with brain findings of amyloid plaques containing β-amyloid and neurofibrillary tangles. AD is a complex and heterogeneous disease, influenced by many genetic and environmental factors.

An early-onset variety in 1% to 5% of AD cases is autosomal-dominant and caused by rare mutations in known genes, including PSEN1, PSEN2, and APP. The predominant form of AD is late-onset (age >60-65), which can be familial (15% to 20%) or sporadic. The APOE4 (E4) variant of apolipoprotein E is strongly associated with risk of late-onset AD.

Apolipoprotein E (apoE) has multiple roles, including lipid transport in the blood and the brain. The APOE4 variant increases the risk for late-onset Alzheimer's disease and may contribute to the pathology of the disease through influence on β-amyloid, inflammation, or other processes.

The risk for development of late-onset AD is increased approximately two- to threefold for individuals with one copy of the APOE4 variant and by approximately 10- to 15-fold for individuals with two copies of the variant (E4/E4 genotype). The APOE2 variant has some protective effect against development of late-onset AD. The lifetime risk for late-onset Alzheimer's disease is approximately 10% to 12% in the general population, though it is higher in women than men and doubles when there is a first-degree relative with this disorder. The lifetime risk is approximately 9% for individuals negative for APOE4, and for individuals with E4/E4 may be as high as 25% for males and 45% for females. Among patients with late-onset AD, the presence of APOE4 may lead to earlier development of symptoms.

However, APOE4 is neither necessary nor sufficient for the development of Alzheimer's disease. Approximately 30% to 50% of patients with late-onset Alzheimer's disease do not have an APOE4 allele. APOE4 is common, with 25% of the general population having one copy and 1% having two copies of this variant. Among patients with late-onset AD, 50% to 70% are positive for APOE4.

The development of late-onset Alzheimer's disease is influenced by many factors other than APOE4, including age, gender, family history, level of education, and history of head trauma. Midlife cardiovascular risk factors in individuals with APOE4 also increase risk for cognitive decline. A number of genetic influences on Alzheimer's development in addition to APOE4 have also been reported and are under investigation. APOE4 is also associated with poor outcome to brain trauma, and it can influence therapeutic response to drugs for AD.

  
This test may require preauthorization from the insurance provider. Check the payer guidelines and, if needed, obtain the pre-authorization prior to sample collection.
  
81401
  
  
Result 49549-9
  
06/03/2019
  
06/02/2020
  
05/19/2020