Genes behind stroke
doi:10.1038/nindia.2011.36 Published online 11 March 2011
Researchers have discovered variations in two genes whose coded proteins control blood pressure, helping to identify an individual's susceptibility to ischemic and haemorrhagic stroke.
Ischemic stroke occurs when a blood vessel that supplies blood to the brain is blocked by a blood clot. Haemorrhagic stroke occurs when a blood vessel in part of the brain becomes weak and bursts open, causing blood to leak into the brain. Ischemic stroke accounts for around 87% of all cases. To find out what causes such strokes, the researchers looked at variations in genes whose coded proteins have roles in controlling blood pressure.
The researchers studied a total of 386 stroke patients, of which 193 had ischemic stroke and intracerebral haemorrhage. To pinpoint variations in the two genes — ACE and ADD1 — they used polymerase chain reaction to compare genetic variations between the stoke patients and control patients.
The ACE gene encodes angiotensin-converting enzyme (ACE), which is involved in catalysing the conversion of angiotensin I into a physiologically active peptide angiotensin II. Angiotensin II controls blood pressure and fluid-electrolyte balance. Adducin belongs to a class of proteins encoded by three genes (ADD1, ADD2 and ADD3). The interaction of ADD1 and ADD3 gene variants is linked to variations in blood pressure.
The researchers found that a specific variation in the ACE gene was significantly higher in ischemic stroke and intracerebral haemorrhage patients than in control patients. The researchers say that such genetic variations in the ACE gene increase the risks of ischemic and haemorrhagic stroke.
- Kalita, J. et al. A study of ACE and ADD1 polymorphism in ischemic and hemorrhagic stroke. Clin. Chim. Acta. 412, 642-646 (2011)