KARACHI, Nov 16: Aga Khan University’s genetic researchers claim to have traced a gene involved in the modulation of high blood pressure.

It is claimed that the new finding will make it possible for experts to predict that which individuals will respond to a particular treatment better. It may also contribute to form the basis for the development of generic tests aimed at assessing an individual’s genetic susceptibility to essential hypertension.

Essential hypertension or high blood pressure with unspecific cause, has become a major health problem in the country, affecting 18 per cent of its population, aged over 15 years, and one out of every three persons above 45 years. It poses a serious risk of heart attack, stroke, and kidney failure to the patients.

While the condition has genetic causes, environmental factors, such as diet, stress and lack of exercise also contribute to its development. This complex interplay of variable factors has so far eluded most attempts at identifying the molecular basis of essential hypertension.

While various drugs are available for blood pressure control, any one drug is effective in only 50 per cent or less of the cases, indicating a poor match between pharmacological action and the underlying mechanism of the disease.

The ‘Gateway Markers and Complex Disorders Research Group’ At the AKU, claims that an individual variation in the angiotensin-converting enzyme (ACE) gene is associated with an inherited tendency to develop high blood pressure.

The ACE gene was involved in generating the active form of a hormone, angiotensin-II, which played a major role in the regulation of vascular tone and blood volume - the two key determinants of blood pressure, the group said.

Drugs that inhibit the formation of angiotensin-II, by blocking ACE, are often used in the treatment of essential hypertension (they form a class of anti-hypertension drugs known as “ACE Inhibitors.”)

One of the major problems associated with treatment of hypertension is that currently there is no effective determinant available for which drugs should be used. This research into the ACE gene has resulted in identification of a genetic marker for hypertension, which may be used as part of a genetic test, for more specifically identifying patients who are likely to benefit from ‘ACE inhibitor’ therapy.

According to the researchers, the work provides clues to the molecular mechanisms underlying hypertension and suggests that an individual’s genetic susceptibility may result from elevated ACE levels, in people inheriting a particular variant of the gene.

The work was led by Professor Philippe Frossard, Director of the group and chairman, Department of Biological and Biomedical Sciences at the AKU, and Dr Mohammed Saeed, BBS instructor, who is also the chief coordinator of the group and the director of this project.

Other key scientists involved in the project were Dr Syed Osman Ali, and Kausar Saboohi. —APP