Gene Identified as Risk Factor for Heart Ills

Two rival teams of scientists have discovered a common genetic variation that increases the risk of heart disease up to 60 percent in people of European descent.

The scientists say they hope a test for the variant can be developed to enable doctors to assess patients at risk more accurately and to recommend early interventions like cholesterol-lowering statins and methods to reduce blood pressure. Heart disease is the leading cause of death worldwide.

The genetic variant is so common that some 50 percent of people in European populations carry one copy of it, and about 20 percent of people have inherited two copies, one from each parent. It is much less prevalent in people of African descent, the scientists said.

How it works is not yet known, but carriers of a single copy have a 15 percent to 20 percent greater risk of heart disease, while those with two copies are up to 60 percent more likely to develop heart disease than people who have none. The risk is even higher for people who suffer a heart attack at an early age, defined as men under 50 and women under 60.

The new finding, published online yesterday in the journal Science, is one of a spate of discoveries about the genetic bases of common diseases. Last week seven new genetic variants involved in the most common form of diabetes were identified, and a batch of new genes from other common diseases is expected...

But as if to prove how much remains to be understood about human biology, the snips lie in a stretch of DNA that contains no gene or genetic element with known functional purpose. It is only on the basis of rigorous statistics that the two groups believe their snips must be causally associated with heart disease.

A Common Allele on Chromosome 9 Associated with Coronary Heart Disease

"Coronary heart disease (CHD) is a major cause of death in Western countries. Here we used genome-wide association scanning to identify a 58 kilobase interval on chromosome 9p21 that was consistently associated with CHD in six independent samples (n> 23,000 participants) from four Caucasian populations. This interval, which is located near the CDKN2A and CDKN2B genes, contains no annotated genes and is not associated with established CHD risk factors such as plasma lipoproteins, hypertension or diabetes. Homozygotes for the risk allele comprise 20-25% of Caucasians and have a ~30-40% increased risk of CHD."

A Common Variant on Chromosome 9p21 Affects the Risk of Myocardial Infarction

"The global endemic of cardiovascular diseases calls for improved risk assessment and treatment. Here we describe an association between myocardial infarction (MI) and a common sequence variant on chromosome 9p21. This study included a total of 4587 cases and 12,769 controls. The identified variant, adjacent to the tumor suppressor genes CDKN2A and CDKN2B, was associated to the disease with high significance (P = 1.2 x 10-20). Approximately 21% of individuals in the population are homozygous for this variant and they have an estimated 1.64-fold greater risk of suffering myocardial infarction than non-carriers. The corresponding risk is 2.02-fold for early onset cases. The population attributable risk (PAR) is 21% for MI in general and 31% for early onset cases."

I found links that I made to recent abstracts that no longer function, so I might as well print brief abstracts.

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