Related Experiment Video
Updated: Feb 1, 2026
09:17
Using Retinal Imaging to Study Dementia
Published on: November 6, 2017
22.3K
Next Generation Sequencing Analysis in Early Onset Dementia Patients
Cristian Bonvicini1, Catia Scassellati1, Luisa Benussi1
1Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.
Journal of Alzheimer'S Disease : JAD
|December 12, 2018
Summary
Early onset dementias (EOD) are linked to a higher probability of carrying polygenic risk alleles compared to late onset forms. Genetic risk factors identified in late onset Alzheimer's disease may also influence early onset dementia risk.
Area of Science:
- Neurogenetics
- Neurodegenerative Diseases
- Genomics
Background:
- Early onset dementias (EOD) are rare neurodegenerative conditions presenting before age 65.
- Genetic factors play a more significant role in EOD pathogenesis than in late-onset dementia.
Purpose of the Study:
- To identify known and novel rare variants in key EOD-associated genes using high-throughput sequencing.
- To assess common-risk variants in apolipoprotein E (APOE) and prion protein (PRNP) genes.
Main Methods:
- Targeted Next-Generation Sequencing (NGS) analysis of 22 EOD patients.
- Progranulin plasma levels, C9Orf72 repeat expansion, and APOE genotyping were performed.
Main Results:
- Three rare pathogenic mutations were found in GRN and PSEN2 genes.
- Eleven unknown-impact mutations were identified in genes including GRN, VCP, MAPT, FUS, TREM2, and NOTCH3.
- EOD patients without fully penetrant mutations showed a higher prevalence of polygenic risk alleles compared to late onset Alzheimer's disease patients and controls.
Conclusions:
- EOD patients without fully penetrant mutations may have a higher polygenic risk burden.
- Genetic risk factors for late-onset Alzheimer's disease might also influence EOD risk.
Related Concept Videos
01:30Dementia
576
Dementia is a collective term for cognitive disorders primarily affecting memory, thinking, and reasoning. It is not a specific disease but a syndrome, with Alzheimer's disease being the most common cause, accounting for approximately 60-80% of cases. Other types include vascular dementia, Lewy body dementia, and frontotemporal dementia. Dementia affects millions worldwide, particularly older adults, though it is not a normal part of aging.
The progression of dementia is generally gradual....
The progression of dementia is generally gradual....
576
03:00Next-generation Sequencing
98.5K
The first human genome sequencing project cost $2.7 billion and was declared complete in 2003, after 15 years of international cooperation and collaboration between several research teams and funding agencies. Today, with the advent of next-generation sequencing technologies, the cost and time of sequencing a human genome have dropped over 100 fold.
Next-Generation Sequencing Methods
Although all next-generation methods use different technologies, they all share a set of standard features....
Next-Generation Sequencing Methods
Although all next-generation methods use different technologies, they all share a set of standard features....
98.5K
02:02Cis-regulatory Sequences
11.8K
Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are...
11.8K
02:02Cis-regulatory Sequences
4.1K
4.1K
01:29Sequences
275
Sequences are fundamental mathematical objects consisting of ordered lists of numbers that follow a specific rule or pattern. Sequences are critical in various mathematical concepts, including calculus, series, and number theory. They can model real-world phenomena such as population growth, financial investments, and physical processes like the diminishing height of a bouncing ball.Each number in a sequence is referred to as a term. Typically, the terms are denoted as a1, a2, a3,…, where...
275
01:57Sanger Sequencing
774.5K
DNA sequencing is a fundamental technique that is routinely used in the biological sciences. This method can be applied to a range of questions at different scales - from the sequencing of a cloned DNA fragment or the study of a mutation in a gene up to whole-genome sequencing. However, despite the widespread use of sequencing today, it was not until 1977 that Fredrick Sanger and his collaborators developed the chain-termination method to decode DNA sequences. It relies on the separation of a...
774.5K