deCODE Complete

Scientists have discovered genetic variants associated with increased risk of developing Systemic Lupus Erythematosus, the most common type of Lupus.

The deCODE Complete Scan analyzes your patients’ DNA, identifies these genetic variants, and uses them to provide you with a personalized interpretation of their genetic risk for developing Lupus.

Systemic Lupus Erythematosus is a complex disease and often difficult to diagnose – knowing your patients’ genetic risk may help rule out or confirm Lupus

Lupus is a disease of the immune system

Lupus is an autoimmune disease characterized by intermittent flares of inflammation in various tissues of the body. Autoimmune diseases occur when the body’s tissues are attacked by its own immune system. Normally, people produce antibodies that attach themselves to infectious agents when they enter the body and mark them for destruction by the immune system. People who have Lupus produce abnormal antibodies that target tissues within their own body. Lupus can therefore cause inflammation and tissue damage in various organs such as the skin, heart, lungs, kidneys, joints, and even the nervous system.

Lupus means wolf in Latin

Over half of people with Lupus develop a characteristic red skin rash over the bridge of their nose. Due to its shape, it is frequently referred to as the “butterfly rash” of Lupus. The term Lupus (Latin for wolf) is however, attributed to physicians of the Middle Ages who used it to describe the erosive skin lesions that they found reminiscent of a wolf’s bite. More on the history of Lupus can be found here.

Systemic Lupus Erythematosus is the most common form of Lupus

There are several types of Lupus. The most common is Systemic Lupus Erythematosus (SLE) which is the disease most often referred to when the term Lupus is used. Systemic indicates that this type of Lupus affects many organs or systems of the body. Erythematosus in Latin means red, and refers to the redness of the facial skin rash so common in Lupus. In addition to a facial rash, Lupus patients usually have joint inflammation (arthritis), as well as fatigue and intermittent fever. The symptoms of Lupus vary from mild to severe, but can flare up between periods of stability. Although Lupus is usually first diagnosed in people between the ages of 15 and 45 years, it can arise in childhood or later in life as well.

Other, less common types of Lupus are:

• Discoid Lupus Erythematosus is a chronic skin disorder in which a red, raised rash appears on the face, scalp, or elsewhere. The raised areas often become thick and scaly and may cause scarring. The rash may last for days or years and may recur. A small percentage of people with Discoid Lupus also have Systemic Lupus Erythematosus or develop it later.
• Subacute Cutaneous Lupus Erythematosus refers to skin lesions that appear on parts of the body exposed to sun. These lesions do not cause scarring.
• Drug-induced Lupus is a form of Lupus caused by various medications. Symptoms are similar to those of Systemic Lupus Erythematosus (arthritis, rash, fever) and they typically go away completely when use of the offending drug is stopped.
• Neonatal Lupus is a very rare disease that can occur in newborn babies of women with Systemic Lupus Erythematosus, Sjögren’s syndrome, or women without these diseases.

Lupus is more common in women than men

It is believed that 5 million people throughout the world are affected by Lupus. The disease mostly affects women of childbearing age (15-44). However, men, children, and teenagers develop Lupus, too. For unknown reasons, the number of people who have Lupus varies widely among different populations. Women are about eight to ten times more likely than men to develop Lupus, and it is also more common in women of African American, Hispanic, Asian, and Native American descent, than in women of European descent.

Genetics play a significant role in the development of Lupus

Systemic Lupus Erythematosus is among the most heritable of the common autoimmune diseases. Genetic factors have been identified that increase the risk of autoimmune diseases such as Lupus, Rheumatoid Arthritis, and autoimmune thyroid disorders. This is reflected by the fact that these autoimmune diseases are more common among relatives of Lupus patients than the general population. Scientists believe that in Lupus, genetic factors predispose the immune system to become more easily stimulated by external factors like viruses, ultraviolet sunlight and drugs, or internal factors such as hormones.

Many common genetic variants increase the risk of developing Lupus

In recent years, scientists have discovered several genetic variants that increase the risk of developing Systemic Lupus Erythematosus; located on chromosomes 1, 2, 6, 7, 8, 11 and 16. One of the variants on chromosome 6 is a surrogate for the HLA*DR3 (DRB1*0301) allele which has been consistently associated with Systemic Lupus Erythematosus.

Some of the variants associating with increased risk of Systemic Lupus Erythematosus are also associated with increased risk of developing other disease; two of the variants, on chromosomes 1 and 2, associate with Rheumatoid Arthritis, another on chromosome 1 associates with Ulcerative Colitis, and yet another variant on chromosome 7 associates with Type 2 Diabetes

deCODEhealth calculates your patients’ genetic risk of developing Systemic Lupus Erythematosus

The deCODE Complete Scan identifies all validated SLE risk variants and uses them to provide a personalized interpretation of the associated genetic risk for developing the disease. The number of variants included in the deCODE Complete Scan for each ethnic group are listed in the table below.

	Number of Variants Measured
European ancestry	13

At present, the necessary scientific information to interpret the genetic risk for individuals of other ethnicities is not available. This information will be added as soon as it becomes available and we are assured of its quality.

This content was last reviewed on February 20, 2012.