Scientists discover gene for high blood pressure

A gene causing drastic hypertension and short fingers has been identified
Berlin researchers from the Max Delbrück Center for Molecular Medicine (MDC) and the Charité have discovered a gene that triggers a severe form of high blood pressure. At the same time it causes "brachydactyly", short finger. The findings may also help high blood pressure patients who are not suffering from the genetic defect.

Rare form of hereditary hypertension is caused by a particular gene
When a patient is first diagnosed as having high blood pressure in a patient, there is a high probability that he or she will respond with a phrase like "This is in our family". Because often not only a family member is affected. Meanwhile, we know that 60 percent of blood pressure is affected by genes. Normally, however, only the "inclination" of the blood is inherited to flow with too much pressure through the vessels. Only factors such as overweight, lack of exercise and a high-salt diet then cause hypertension. Often a change to a healthier lifestyle is already an improvement.

Overview of possible heart diseases. Picture Henrie / fotolia

Usually, high blood pressure is not caused by just one gene. Rather, the regulation of blood pressure depends on several genes. An exception is a rare form of hereditary high blood pressure, which researchers around Friedrich Luft from the Max Delbrück Center for Molecular Medicine (MDC) and the Charité recently came to terms with. For almost two decades, they have dedicated their research to a specific but long-unknown gene whose location they could encircle in a region of chromosome 12. After sequencing the genome of some individuals, they succeeded in identifying the gene that causes not only severe hypertension but also malformations of the finger bones in all those carrying it.

Gene triggers hypertension by altering the vascular muscle cells
"When we started researching this disease in 1994 and were studying the largest of the affected families for the first time in Turkey, there was neither the modern methods of gene sequencing nor the extensive gene databases," reports Sylvia Bähring, the final author of the publication from the research group of Luft the long search for the cause of hereditary disease. "In the end, however, a 16-year-old Turkish boy took us on the trail of the gene. He is virtually our gold treasure of genetics. "The researcher explained:" The special point mutation that it shows in the gene PDE3A, affects mainly on the blood pressure, but hardly on the skeleton ".

This is the first form of hypertension inherited according to Mendelian rules, which causes problems not because of salt, kidney function and the complicated renin-angiotensin system, but because of the peculiarities of the vessels. Because the gene PDE3A triggers an increased activity of the muscle cells of the blood vessels and a change in their structure. Bähring therefore advises to concentrate more on the vessels and their peculiarities in the study of the "common disease" hypertension. "We have shown in our study that only the blood vessels are important for the genesis of this genetically inherited form of hypertension and not the kidney directly," says Bähring. Even in high blood pressure patients who have no genetic specificity, salt does not always play a role. "Perhaps some of them also have a hyperactivity of the enzyme in the vascular muscle cells, which we found in the families with the altered gene," quotes "tagesspiegel.de" the scientist.

Only six families worldwide are aware of the genetic defect
So far, only six families worldwide are known to suffer from the genetic defect. Already at a young age, they suffer from extremely high blood pressure levels and succumb to a stroke - without medical treatment - before the age of 50. In addition, they have remarkably short fingers, because the gene PDE3A not only affects high blood pressure, but also the growth of cartilage cells and thus the length of the fingers.

In the next step, the researchers want to take a close look at the behavior of the gene in the vascular muscle cells and find out whether this can be specifically counteracted. Luft and his colleagues published their findings in the journal Nature Genetics. (Ag)