Gene panel (includes 1 gene)
APOE (OMIM# 107741)

Basic characteristics of the clinical phenotype

Alzheimer's disease (AD) is the most common progressive neurodegenerative disease affecting the central nervous system, particularly cortical degeneration. It is characterized by progressive dementia, cognitive disorders, difficult decision-making, hallucinations, psychiatric disorders, confusion, speech disorders, etc. Accumulation of amyloid plaques and neurofibrillary tangles are observed, leading to degeneration of neurons.

According to the mode of inheritance in family cases, autosomal-dominant and autosomal-recessive types are observed. According to the onset of the disease, it is divided into Alzheimer's disease with early onset - 60-65 years of age (5%) and Alzheimer's disease with late onset - after 60-65 years of age (95%).

The APOE gene codes for a protein called apolipoprotein E, which combines with fats (lipids) in the body to form molecules called lipoproteins. They, in turn, are responsible for packaging cholesterol and other fats and carrying them through the bloodstream. Maintaining normal cholesterol levels is essential to prevent disorders that affect the heart and blood vessels (cardiovascular disease), including heart attack and stroke.
There are at least three slightly different APOE alleles. The major alleles are called E2, E3 and E4. The most common allele is E3, which occurs in more than half of the general population. The E4 allele of the APOE gene increases the risk of developing late-stage Alzheimer's disease.

Reasons for referring:
Presence of dementia, family history of AD, suspicion of AD, confirmation of AD diagnosis

Interpretation of results:
Inheritance of one copy of the E4 allele of APOE increases the risk of developing AD; Inheriting both copies of the allele further increases the risk of developing this disease
The E4 APOE allele may also be associated with an earlier onset of memory loss and other symptoms compared to people with Alzheimer's disease who do not have this allele; People with the E4 allele of APOE inherit an increased risk of developing AD, not the disease itself. Not all people with Alzheimer's disease have the APOE E4 allele, and not all people who have this allele will develop the disease.

Method: Sanger sequencing.
The method involves bi-directional DNA sequencing of all coding exons and intron-exon boundaries of the APOE gene. The laboratory offers single exon sequencing in relatives of patients to determine carrier status in cases where the mutation is known (Test #182).

Sensitivity of the method: 99.5%

What does the test involve?

· DNA isolation and sample storage.
· Direct sequencing of target genes/gene regions to detect pathogenic mutations.
· Forming a written result of the genetic test.
· Diagnostic interpretation of results and genetic counseling.

Biological material: Venous blood or DNA

For more information, please read the "Biological material requirements and shipping information" carefully.