Researchers from the International Stroke Genetics Consortium (ISGC), among them scientists from the Vall d’Hebron Research Institute (VHIR), the Hospital del Mar Medical Research Institute (IMIM), and the Research Foundation MutuaTerrassa (FMT) of the University Hospital MutuaTerrassa (HUMT) have identified a new gene, PMF1, involved in intracerebral haemorrhage. The finding, published in the American Journal of Human Genetics, was possible thanks to the first genome-wide association study (GWAS) on this disease.
The researchers performed a meta-analysis on the genetic information obtained in six genome studies carried out in the US and Europe on 1,545 patients of European ancestry with one of the two types of haemorrhagic stroke –lobar and non-lobar– and on 1,481 healthy patients in the control group. Until then, they knew that common genetic variations played a substantial role in the two types of haemorrhagic stroke, but there had never been a study analysing all the genes in such a comprehensive way.
Thanks to this work, the researches have been able to detect a genetic variation in chromosome 1q22 associated with patients with non-lobar haemorrhagic strokes. For Dr Israel Fernández, member of the Neurovascular Diseases research group of the VHIR and head of the Pharmacogenomics and Neurovascular Genetics laboratory of the FMT, “the gene identified (PMF1) may constitute a new risk factor for this disease because it may be related to the breakdown of the blood-brain barrier associated with this type of haemorrhagic stroke”.
There is currently no effective treatment for intracerebral stroke, which is the most common type of haemorrhagic stroke. It is not known how the mechanisms that cause its appearance function but it is known that there are many risk factors such as hypertension, amyloid angiopathy and the use of anticoagulant drug treatments.
“Furthermore, we have found that different genetic variants are associated with haemorrhages in specific locations in the brain. This can help us to characterise and better understand the different causes of the disease and, therefore, provide us with clues to prevent it or to treat it”, adds Dr Jordi Jiménez, researcher of the IMIM Neurovascular Research Group and a neurologist at the Hospital del Mar.
With this discovery, Dr Fernández states that “the door has been opened to the analysis of new metabolic pathways to develop future drugs for this disease and reduce the heavy strain that it places on society.
Haemorrhagic stroke is produced by a rupture in the cerebral blood vessels and mainly affects the elderly. As there is no available treatment, its evolution is worse than in ischaemic strokes: the mortality rate in patients who suffer a haemorrhagic stroke is between 40 and 50 percent in the first three months and it causes sustained disability in half of the survivors. Furthermore, according to recent research, its incidence is expected to increase in the next few years due to the increase in life expectancy and the widespread use of thrombotic treatments among the elderly.
In Catalonia and Spain the incidence of haemorrhagic strokes is approximately 30-40 cases per 100,000 inhabitants, although the frequency increases in the higher age ranges.