HYPERTENSION GENE IDENTIFIED

                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: THURSDAY, January 16, 1992                   TAG: 9201160051
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A-7   EDITION: METRO 
SOURCE: Associated Press
DATELINE: SALT LAKE CITY                                LENGTH: Medium
HYPERTENSION GENE IDENTIFIED
Researchers said Wednesday that they have pinpointed a genetic mixup responsible for a rare form of hypertension. Their study is the first to show a specific gene causing high blood pressure.
The find, reported in the British journal Nature, may lend hope to the estimated 60 million Americans with high blood pressure, said geneticist and co-author Dr. Richard P. Lifton.
"While hypertension is a heterogeneous disorder with many, many causes, this shows progress can be made," said Lifton.
"The big message is that this is the first example where we've been able to identify a specific genetic cause of high blood pressure."
The researchers isolated a "chimeric" gene that causes glucocorticoid-remediable aldosteronism, or GRA, which causes high blood pressure at an early age. Sufferers often die young from strokes, heart attacks or kidney failure.
Lifton said the number of people with GRA is not known.
"It certainly is only a small fraction of those who suffer from hypertension," he said. "But we believe it is underdiagnosed."
Isolating the gene will let doctors easily diagnose the malady, which is treatable with hormones. Patients generally don't respond well to more common blood pressure treatments.
"Up to now we've treated it as something of a black box, using any one of the 30 or so hypertension medicines in our arsenal to deal with," he said. "These more commonly used drugs don't sit on it very well.
"We don't think it will account for anything like 50 percent" of those who suffer from hypertension, he said. "But when you're dealing with 60 million people, a tiny percentage will add up to helping thousands."
More importantly, Lifton said, the discovery "provides a foot in the door" for research into what role genetics plays in more common forms of hypertension.
He said research will turn toward identifying those with GRA and look into the possibility that less drastically altered genes might be responsible for other types of hypertension.
Lifton said research into the phenomenon began two years ago when Dr. Robert Dluhy of Brigham and Women's Hospital in Boston found a large family affected with the disorder.
The researchers isolated a mutant gene that Lifton likened to the mythological Minotaur, which had a bull's head and man's body.
"They fuse, and what you end up with is the head of a gene that regulates one bodily function, and the body of another, which determines the creation of a specific protein," he said.
The defective gene causes the adrenal gland to produce unregulated amounts of a hormone called aldosterone, which causes the kidneys to retain salt and water.
"It fills up the blood vessel much too full, causing the pressure to soar," he said.

by Archana Subramaniam by CNB