Heart Disease Gene Traced to One Ancestor

Persistence really pays off, and this is especially true in genetic studies. After 35 years of combined research, a father-and-son team has finally identified the source of the gene that causes the heart’s electricity to go awry.

For three hundred years, a South African family has been plagued by progressive familial heart block, a disease of the electrical system of the heart. The disease causes an affected person to have irregular heart beats, fainting spells, seizures or sudden death. The risk is greatest soon after birth, during puberty and early twenties and returns in the middle age, and a timely installment of a pacemaker is the best treatment.

Using data from the human genome project, Professors Andries and Paul Brink were able to trace the origin of this disease to one man: A Portuguese emigrant who married a Dutch woman and lived in the Cape in 1964. His descendants now live throughout South Africa and unfortunately inherited this dominant trait. The scientists identified 85 living descendants who carry the gene in their genome, and although that’s a small number, it’s still very important for the people involved to know their risk from being carriers.

A heart block disease is different from a coronary heart disease (CHD). Whereas a CHD is caused by problems in the blood vessels of the heart, a heart block stems from problems with the electrical conduction inside. A pacemaker gives a regulated electrical current to keep the heartbeat steady.

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