Iranian family key to fatal heart gene

A large extended family with a history of serious heart disease and premature deaths has provided scientists with a unique insight into the single biggest killer disease in Britain.

The family, who live in Tehran, has a rare genetic mutation that kills most of its members in middle age from heart disease. A joint study by a team of American and Iranian doctors identified the precise mutation in the family's DNA that leads to high blood pressure, high cholesterol, diabetes and heart failure.

The findings may help to explain the reasons why some people develop heart disease while their close relatives remain free of the life-threatening illness, the scientists said.

The study has also established a direct link between heart problems and the bone-thinning disease, osteoporosis, that could explain why some people suffer from both conditions at the same time. "There is emerging recognition that osteoporosis and coronary artery disease occur together more often than expected by chance," said Richard Lifton of Yale University School of Medicine, who led the study published in the journal Science.

Doctors in Tehran have known of the family's heart disease problem for many years. Twenty-three of the 28 blood relatives of the first patient identified with the genetic mutation died at an average age of just 52.

Heart disease is influenced by a complicated range of factors, from the inheritance of subtly different genes from one's parents, and environmental influences in the womb, to the effects of diet and lifestyle.

Finding a single genetic mutation behind such a strong family history of heart disease is rare, and could help scientists to unravel the metabolic pathways in the body responsible for increasing the risk of heart disease.