SCIENCE

Tracking a genetic error

BRUCE WALLACE September 28 1987
SCIENCE

Tracking a genetic error

BRUCE WALLACE September 28 1987

Tracking a genetic error

SCIENCE

The landmark study traces the roots of a deadly disease all the way back to the founders of 17thcentury New France. Last week a team of Quebec and Texan researchers reported in the Sept. 17 issue of the Bostonbased New England Journal of Medicine that they had identified a single genetic defect as the cause of one form of a condition called familial hypercholesterolemia among 63 per cent of a study group of 84 French Canadians. The researchers found that 53 of the patients—who were not related—had an identical genetic mutation that can result in high cholesterol levels and heart attacks at an early age. And they say that their discovery will enable doctors to identify the defect in family members and prevent the early onset of heart disease by controlling cholesterol levels through drug and diet therapy.

The five-member research team, which included two Nobel Prize winners and Montreal’s Dr. Jean Davignon, a leading cholesterol researcher and coauthor of the report, studied blood samples taken from Montreal-area francophones who were being treated for abnormally high cholesterol levels at Montreal’s world-renowned Clinical Research Institute. The relatively rare genetic error—which occurs in only one of every 500 people worldwide—appears in one of the body’s two low-density lipoprotein receptor genes, which cleanse the blood of cholesterol. With the body’s defence system weakened, the resulting cholesterol buildup in arteries increases the likelihood of early—and often fatal—heart attacks. Declared Dr. Anna Kessling, an assistant to Davignon: “This discovery will greatly increase our ability to diagnose patients and may help us in developing drugs that can control the disease.”

The scientists attributed the condition to the legacy of intermarriage among the small pool of 8,000 French colonists who emigrated to what later became Canada between 1608 and 1763. Said Davignon: “Among a people where there is a great deal of intermarriage and little population movement, genetic defects occur more frequently.” But the new findings now offer hope to French Canadians afflicted by a lethal inheritance from their ancestors.

BRUCE WALLACE