'Preimplantation Genetic Diagnosis 2018: Current Practice and Beyond', 9-10 November 2018
Page URL: https://www.bionews.org.uk/page_92888

Gene linked to early onset stroke uncovered

21 March 2011
Appeared in BioNews 600

US scientists have identified a gene that may increase the risk of an early onset of stroke. They analysed the genomes of 14 Amish people affected by stroke and found a mutation in the SAMHD1 gene was associated with this brain condition.

The study was conducted at the DDC Clinic for Special Needs Children in Ohio and was led by the clinic's Medical Director, Dr Heng Wang. The participants all suffered from cerebral vasculopathy - a disease of the blood vessels in the brain - which led to early stroke, but the severity of brain damage after the stroke varied widely. Some showed severe developmental disability, while others did not. Each person also showed signs of an immune system disorder.

The gene mutation was identified using a technique called genome-wide homozygosity mapping. This technique is used for studying recessive genetic disorders - where two copies of the mutation must be inherited together before the disease manifests. It involves comparing the genomes of distantly-related people to find stretches of DNA that are identical.

The assumption is that affected individuals who share a common ancestor are likely to have inherited the exact same mutation from their parents. Shared regions of the genome between those affected are therefore highly likely to contain the culprit gene.

The Old Order Amish are unique participants in homozygosity mapping studies because a tradition of marrying within the community has led to a genetically similar population, with most Amish having descended from a small founder population. As a result, the incidence of genetic diseases in the Amish population is higher than normal.

The homozygosity mapping identified a region on chromosome 20 that was identical in the 14 Amish participants. The researchers sequenced each gene located within this region and found a mutation in the SAMHD1 gene. The mutation leads to the production of an abnormal protein in which a large section has been deleted. The exact function of SAMHD1 is currently unknown, but Dr Wang and colleagues believe it must play a role in maintaining the blood vessels in the brain.

'The function of SAMHD1 remains unclear, but the inflammatory (blood vessel abnormalities) of the brain found in the patients with SAMHD1 mutation indicate its important roles in (the regulation of the immune system) and cerebral (blood vessel maintenance)', said Dr Wang.

As this mutation was identified in a genetically isolated community, further work is needed to see if it is present in other populations.

The research was published online this week in the Proceedings of the National Academy of Sciences.

SOURCES & REFERENCES
Homozygous mutation in SAMHD1 gene causes cerebral vasculopathy and early onset stroke
PNAS |  14 March 2011
RELATED ARTICLES FROM THE BIONEWS ARCHIVE
18 March 2013 - by Antony Blackburn-Starza 
A genetic mutation linked to mental retardation has been identified in an Amish community in the USA....
13 February 2012 - by Luciana Strait 
A genetic variant has been linked to an increased risk of a common type of stroke. Researchers identified an alteration in a gene called HDAC9 that is more common in people who have had an ischaemic stroke than in those who have not. The study also replicated variants previously associated with subtypes of ischaemic strokes...
5 September 2011 - by Alison Cranage 
A pioneering clinical trial to inject stem cells into the brains of disabled stroke patients has been cleared to progress to the next stage after no safety concerns were raised in the first three patients....
29 November 2010 - by Dr Rachael Panizzo 
A British man has become the first patient in the world to receive a pioneering stem cell therapy to repair brain damage caused by stroke....
10 May 2010 - by Dr Marianne Kennedy 
Certain variations of mitochondrial DNA are protective against strokes, according to a recent study in The Lancet Neurology....
20 April 2009 - by Rosie Beauchamp 
A study by an international research team, published a study this week in The New England Journal of Medicine, identifies for the first time a genetic variant that leads to an increased chance of stroke. Stroke is the third leading cause of death in the US and...
22 September 2008 - by Dr Charlotte Maden 
A group of US researchers have found that injecting human stem cells derived from bone marrow into the brain after it has suffered a stroke can alleviate symptoms. The research was carried out at the Center for Gene Therapy, Tulane University, New Orleans, and reported in Proceedings...
4 August 2008 - by Stuart Scott 
A gene variant previously thought to increase the risk of migraine in women has been shown, in fact, to have a mildly protective effect, according to a new study published in the journal Neurology. However, the study also shows that if women go on to develop migraines...
HAVE YOUR SAY
Log in to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions


Syndicate this story - click here to enquire about using this story.