A core assumption in the study of disease-causing genes has been that they are clustered in molecular pathways directly connected to the disease. But work by a group of researchers suggests otherwise.
The gene activity of cells is so broadly networked that virtually any gene can influence disease, the researchers found. As a result, most of the heritability of diseases is due not to a handful of core genes, but to tiny contributions from vast numbers of peripheral genes that function outside disease pathways.
Any given trait, it seems, is not controlled by a small set of genes. Instead, nearly every gene in the genome influences everything about us. The effects may be tiny, but they add up according to the work is described in a paper published in Cell.
The researchers call their provocative new understanding of disease genes an "omnigenic model" to indicate that almost any gene can influence diseases and other complex traits. In any cell, there might be 50 to 100 core genes with direct effects on a given trait, as well as easily another 10,000 peripheral genes that are expressed in the same cell with indirect effects on that trait, said the senior author.
Each of the peripheral genes has a small effect on the trait. But because those thousands of genes outnumber the core genes by orders of magnitude, most of the genetic variation related to diseases and other traits comes from the thousands of peripheral genes. So, ironically, the genes whose impact on disease is most indirect and small end up being responsible for most of the inheritance patterns of the disease.
Until recently, said the senior author, everyone thought of genetically complex traits as conforming to a polygenic model, in which each gene has a direct effect on a trait, whether that trait is something like height or a disease, such as autism.
In the earlier work on the genetics of height, researchers were surprised to find that essentially the entire genome influenced height. "It was really unintuitive to me,"senior author said. "To be honest, I thought that it was probably wrong." The team spent a long time trying to understand the surprising result.
The polygenic model leads researchers to focus on the short list of core genes that function in molecular pathways known to impact diseases. So, therapeutic research typically means addressing those core genes. A common approach to gene discovery is to do larger and larger genomewide association studies, the paper notes, but the team argues against this approach because the sample sizes are expensive and the thousands of peripheral genes uncovered are likely to have tiny, indirect effects. "After you get the first 100 hits," said the senior author, "you've probably found most of the core genes you're going to get through genomewide association studies."
Instead, the senior author recommends switching to deep sequencing the core genes to hunt down rare variants that might have bigger effects. For clinical use, there's still a rationale for genomewide association studies: to predict the peripheral gene-based risk factors in individual patients in order to personalize medicine.
The omnigenic model promises to take basic biology in new directions and means biologists need to think a lot more about the structure of networks that link together those thousands of peripheral disease genes.
"If this model is right," said the senior author, "it's telling us something profound about how cells work that we don't really understand very well. And so maybe that puts us a little bit further away from using genomewide association studies for therapeutics. But in terms of understanding how genetics encodes disease risk, it's really important to understand."
http://med.stanford.edu/news/all-news/2017/06/thousands-of-genes-influence-most-diseases.html
http://www.cell.com/cell/abstract/S0092-8674(17)30629-3
Thousands of genes influence most diseases
- 1,699 views
- Added
Edited
Latest News
Role of ECM in brain memory
By newseditor
Posted 13 May
All individuals with two co…
By newseditor
Posted 12 May
Autoantibody patterns in pa…
By newseditor
Posted 12 May
How brains convert sounds t…
By newseditor
Posted 12 May
Mice with traits of Tourett…
By newseditor
Posted 11 May
Other Top Stories
The genes of the sixth sense
Read more
Neural circuit that enables self-localization in zebrafish
Read more
Newborns' 'Random' Body Movements Are Helping Them Learn
Read more
Brain integrates information coming from the senses
Read more
Managing emotions better could prevent pathological ageing
Read more
Protocols
Mime-seq 2.0: a method to s…
By newseditor
Posted 13 May
Improved detection of DNA r…
By newseditor
Posted 09 May
Single-cell adhesive profil…
By newseditor
Posted 07 May
Parasympathetic neurons der…
By newseditor
Posted 07 May
Non-invasive measurements o…
By newseditor
Posted 05 May
Publications
Antigen-specific Fab profil…
By newseditor
Posted 12 May
Differential representation…
By newseditor
Posted 12 May
Glucose hypometabolism prom…
By newseditor
Posted 12 May
Organellophagy regulates ce…
By newseditor
Posted 12 May
Decoding mitochondria's rol…
By newseditor
Posted 11 May
Presentations
Hydrogels in Drug Delivery
By newseditor
Posted 12 Apr
Lipids
By newseditor
Posted 31 Dec
Cell biology of carbohydrat…
By newseditor
Posted 29 Nov
RNA interference (RNAi)
By newseditor
Posted 23 Oct
RNA structure and functions
By newseditor
Posted 19 Oct
Posters
A chemical biology/modular…
By newseditor
Posted 22 Aug
Single-molecule covalent ma…
By newseditor
Posted 04 Jul
ASCO-2020-HEALTH SERVICES R…
By newseditor
Posted 23 Mar
ASCO-2020-HEAD AND NECK CANCER
By newseditor
Posted 23 Mar
ASCO-2020-GENITOURINARY CAN…
By newseditor
Posted 23 Mar