Breakthrough in national diseases

Common factor behind myocardial infarction, rheumatism and MS

A common gene variant has been identified as the risk factor behind a number of common diseases by research scientists at Karolinska Institutet and the Centre for Molecular Medicine (CMM), Stockholm, Sweden. Up to a quarter of the population could be affected.
Researchers in the fields of cardiovascular disease, rheumatism and MS have together shown that there is a common risk factor for these conditions. It is the first identified gene to link autoimmune diseases with cardiovascular diseases.

“This gene variant can therefore be one of the single largest genetic causes of complex diseases with inflammatory components,” says Fredrik Piehl, associate professor at Karolinska Institutet and researcher at the CMM. “There is also a chance that other diseases are also affected by this gene variant. The discovery can now lead to more reliable diagnostics and better treatments for a great number of patients.”

The gene variant was first identified in an animal model and then studied in a number of patient groups to ascertain if there was a link to human diseases. The researchers discovered that people with the variant ran a 20–40 per cent greater risk of developing rheumatism, MS or a myocardial infarction. The gene variant is also common: an estimated 20–25 per cent of the population carry it.

The discovery reveals a new area of application for statins, drugs usually taken to lower cholesterol levels. Statins have been shown to reduce activity in this gene and thus produce anti-inflammatory effects. Statins have now been tested on MS patients and have been demonstrated to be beneficial in this very way.

The disease-associated gene variant leads to a reduction in the production of a number of immune defence proteins. Some viruses and bacteria have also been observed to influence the gene in an attempt to evade the immune defence system, a strategy employed, for example, by the viruses that cause AIDS, herpes and hepatitis.

The article, entitled “MHC2TA is associated with differential MHC molecule expression and susceptibility to rheumatoid arthritis, multiple sclerosis and myocardial infarction” will be published on the Nature Genetics website on Sunday 10 April at 1.00 p.m. (Eastern US Time).