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Aaltrude
01-09-11, 01:45 AM
From Heather Brannon, MD (http://dermatology.about.com/bio/Heather-Brannon-MD-8905.htm)
Updated January 24, 2010

Psoriasis (http://dermatology.about.com/od/psoriasis/a/psoriasis.htm) is a chronic skin disorder that affects 1% to 3% of the world's population. It is characterized by periodic flare-ups of well defined, red patches covered by a silvery, flaky scale on the extensor surfaces (http://dermatology.about.com/od/glossarye/g/ext_surface.htm) and the scalp. There are several variations of psoriasis but the most common type is chronic plaque psoriasis (http://dermatology.about.com/od/psoriasis/a/PlaquePsoriasis.htm). The exact cause of psoriasis is unknown, but it is believed that a combination of several factors contributes to the development of this disease.

Genetic Causes of Psoriasis

Researchers have found 9 gene mutations that may be involved in causing psoriasis. One of these mutations on chromosome 6, called PSORS-1, appears to be a major factor that can lead to psoriasis. Mutations on genes cause certain cells to function differently. With psoriasis, these mutations seem to largely affect T-helper cells.

Immune System Causes of Psoriasis

In a normally functioning immune system, white blood cells produce antibodies to foreign invaders such as bacteria and viruses. These white blood cells also produce chemicals that aid in healing and fighting infective agents. But with psoriasis, special white blood cells called T-cells become overactive.

These T-cells "attack" the skin and set off a cascade of events that make the skin cells multiply so fast they start to stack up on the surface of the skin. Normal skin cells form, mature, then are sloughed off every 30 days. But in plaque psoriasis the skin goes through this whole process in 3-6 days.
Normally T-cells produce chemicals that help heal the skin. In psoriasis, T-cells produce an abnormally large amount of these chemicals and actually cause more inflammation in the skin and joints. Environmental Causes of Psoriasis

Not everyone who has these gene mutations gets psoriasis and there are several forms of psoriasis that people can develop. Certain environmental triggers play a role in causing psoriasis in people who have these gene mutations. Learn more about other psoriasis triggers (http://dermatology.about.com/od/psoriasis/a/psoriasis_trigg.htm).

http://dermatology.about.com/od/psoriasisbasics/a/psorcause.htm

LabDoc
01-10-11, 11:20 AM
Aaltrude, when gene mutations are mentioned, I always seem to be devils advocate and have to ask - do the gene mutations cause a disorder, or does the disorder cause gene mutations (not only relating to psoriasis). So far I have yet to receive a credible answer from anyone.

Islander
01-10-11, 06:24 PM
Dammit, Aaltrude, you're making me itchy!

mellowsong
01-10-11, 10:48 PM
Aaltrude, when gene mutations are mentioned, I always seem to be devils advocate and have to ask - do the gene mutations cause a disorder, or does the disorder cause gene mutations (not only relating to psoriasis). So far I have yet to receive a credible answer from anyone.

Where's PPARGammagirl when you need her??? Bet she could come up with something, lol.

Reesacat
01-10-11, 10:50 PM
I am still talking to the chicken about the egg...............

Aaltrude
01-10-11, 11:59 PM
Aaltrude, when gene mutations are mentioned, I always seem to be devils advocate and have to ask - do the gene mutations cause a disorder, or does the disorder cause gene mutations (not only relating to psoriasis). So far I have yet to receive a credible answer from anyone.

Good question. The susceptibilty to developing Psoriasis is inherited though therefore genes must involved at some level.