deCODE Complete
Analyzes risk factors for more than fifty common diseases and several traits, including all of those for which deCODEhealth offers individual disease tests. deCODE Complete focuses on medical conditions that can either be better prevented through altered lifestyle or that have better treatment outcomes if detected early. It is the most comprehensive genetic scan available for evaluating risk of common diseases. It is not generally reimbursable.
Diseases and conditions covered by the deCODE Complete Scan:
Abdominal Aortic Aneurysm, ABO Blood Types, Age Related Macular Degeneration, Alcohol Flush Reaction, Alzheimer’s Disease, Asthma, Atrial Fibrillation, Basal Cell Carcinoma, Bitter Taste Perception, Bladder Cancer, Brain Aneurysm, Brain Cancer-Glioma, Breast Cancer, Celiac Disease, Chronic Kidney Disease, Chronic Lymphocytic Leukemia, Chronic Obstructive Pulmonary Disease, Clopidogrel Response, Colorectal Cancer, Crohn’s Disease, Essential Tremor, Exfoliation Glaucoma, Eye Color, Gallstones, Gout, Heart Attack, Hemochromatosis, Hypertension, Kidney Stones, Lactose Intolerance, Lung Cancer, Male Pattern Baldness, Multiple Sclerosis, Nicotine Dependence, Obesity, Ovarian Cancer, Pancreatic Cancer, Peripheral Arterial Disease, Prostate Cancer, Psoriasis, Restless Legs Syndrome, Rheumatoid Arthritis, Statin Induced Myopathy, Systemic Lupus Erythematosus, Testicular Cancer, Thyroid Cancer, Type 1 Diabetes, Type 2 Diabetes, Ulcerative Colitis, Venous Thromboembolism, Warfarin Metabolism.
Psoriasis
Psoriasis is not contagious and it is difficult to say what triggers it.
A family history of psoriasis is the greatest known risk factor.
Smoking, excessive drinking and stress are known to worsen symptoms.
Psoriasis is a chronic inflammotory skin disease
Psoriasis is a chronic inflammatory disorder of the skin, the body’s largest organ and the first line of protection from the environment. Although the direct cause of psoriasis is currently unknown, it results in skin cells growing abnormally fast, causing the skin to shed every three to four days.
An autoimmune disease
There are five types of psoriasis: plaque, guttate, inverse, pustular and erythrodermic. The most common form, plaque psoriasis, is characterized by inflamed, scaly, red, itchy patches called psoriatic plaques. It is a fluctuating condition with recurrent episodes of variable severity. About 10% to 20% of psoriasis patients develop psoriatic arthritis, an inflammatory joint disease.
Psoriasis and psoriatic arthritis are considered to be autoimmune diseases, in which the immune system attacks the body’s own tissues.
Most common among people of European ancestry
Psoriasis is most common among people of European ancestry (with a prevalence of 2% to 3%). Women have a slightly higher risk of developing psoriasis according to some studies. Psoriasis is estimated to affect 5 to 7 million people in the US.
Genetics contribute to the development of Psoriasis
Several genetic variants known to increase the risk of developing psoriasis; including variants located on chromosomes 1, 5, 6, and 12. Of these the variant in the HLA-C gene contributes by far the strongest effect to the risk of developing psoriasis in most if not all populations tested.
deCODEhealth can calculate your patients’ genetic risk
The deCODE Complete Scan identifies validated psoriasis risk variants and uses them to provide a personalized interpretation of the associated genetic risk for 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 | 8 |
| East Asian ancestry | 3 |
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.
Risk factors
Family history is the greatest risk factor
A family history of psoriasis is the greatest risk factor. In a study of identical twins, 70% of twins who had psoriasis had a twin who also had psoriasis. Studying identical twins for concordance (both twins having the same disease) is generally a good measure of genetic contribution since their inherited genetic material (DNA) is identical. A 70% concordance rate is considered to be very high for a condition of complex inheritance such as psoriasis.
A genetic connection exists between psoriasis and the immune system
Psoriasis appears to involve the immune system. Therefore, it is not surprising that the gene most strongly and consistently associated with psoriasis is a gene important in immune response. HLA-C, specifically HLA-Cw6, is associated with psoriasis in most, if not all, populations tested. Commonly, over 60% of psoriasis patients carry one or more copies of the Cw6 variant of HLA-C compared with 8% to 12% of those who do not have psoriasis.
On average, psoriasis patients who have the Cw6 variant tend to develop the disease a few years earlier and can have more severe progression of the disease compared with psoriasis patients who do not have the Cw6 variant. Recently, two other genes, IL-12beta and IL-23R, have been associated with psoriasis, but they do not seem to play as important a role as HLA-Cw6 in their contribution to the risk of developing the disease.
Prevention and treatment
Psoriasis is not contagious. No preventive measures are known to be effective, since not much is known about what triggers the onset of psoriasis. Usually, no obvious trigger is found. Some studies have indicated that an infection (most often a streptococcal infection or "strep throat") can stimulate or perhaps over-stimulate the immune system into a state of self-attack. Several other factors including smoking, excessive drinking, and stress are known to worsen or exacerbate symptoms.
Effective treatments are available
At the present time, there is no cure for psoriasis. There are many treatments available depending on disease severity, ranging from skin moisturizers to immunosuppressive medications. The goal of treatment is to reduce inflammation and slow the rapid growth and shedding of skin cells.
More information
You can find out more information about psoriasis by talking with a doctor and visiting these Web sites:
American Academy of Family Physicians
MedlinePlus Article on Psoriasis
National Institute of Arthritis and Musculoskeletal and Skin Diseases
The National Psoriasis Foundation
This content was last reviewed on February 20, 2012.