Analysis of exons 16 and 17 of the APP gene - the second stage of diagnostics of hereditary Alzheimer's disease

Synevo
- Test description
- Documents
This study is related to the analysis of exons 16 and 17 of the APP gene and the
diagnosis of Alzheimer's disease.
Alzheimer's disease (AD) is a genetic disorder of autosomal dominant inheritance
autosomal dominant. Patients with the inherited form of the disease
Alzheimer's disease (AD) carry mutations in presenilin proteins (PSEN1,
PSEN2) or in amyloid precursor protein (APP).
These mutations result in increased production of the longer form of amyloid
beta (the main component of amyloid deposits found in the brain of
AD patients). At least 11 mutations in the PSEN2 gene have been shown to
causes early-onset Alzheimer's disease, which begins before the age of 65
age. Mutations in this gene account for less than 5 percent of
of all early cases of the disorder.
Two of the most common PSEN2 mutations that cause early
Alzheimer's disease, alter single building blocks
(amino acids) used to make presenilin 2. One mutation
replaces the amino acid asparagine with the amino acid isoleucine at position 141
(Asn141Ile). The other mutation changes the amino acid methionine to the amino acid
valine at position 239 (Met239Val).
These mutations disrupt the processing of amyloid precursor protein,
leading to overproduction of amyloid beta peptide. Copies of this
fragment of the protein stick together and accumulate in the brain, forming clumps
called amyloid plaques, which are a hallmark of
Alzheimer's disease.
The accumulation of toxic β-amyloid peptide and the formation of plaques
amyloid plaques likely leads to neuronal death and
progressive physical and subjective symptoms of this
disorder.