Is Psoriasis Genetic?

The cause of psoriasis, an itchy and painful skin condition that affects 7.5 million Americans, has never been conclusively linked to a genetic process. Scientists have long suspected a genetic connection, but have not been able to isolate the genes and mutations involved—until now. A new study has identified the first gene linked to plaque psoriasis, the most common type that accounts for 80 percent of psoriasis cases. Additionally, they've discovered that this gene may also be linked to pustular psoriasis and arthritic psoriasis.

Scientists have noted that psoriasis runs in families, but since the gene mutations that increase the risk of developing the disease are rare, it's been hard to pinpoint the genes involved. To further complicate things, this disease requires both the genetic risk and a trigger to activate it. Psoriasis can begin at any age, though most people develop it between the ages of 15 and 30. Most psoriasis patients have at least one family member who also has it.

This new study, which was co-authored and funded by multiple researchers and organizations, looked at family histories with high incidences of psoriasis. They isolated the CARD14 gene as the culprit and discovered that mutations in this gene had common threads but also occurred independently. When mutations in the CARD14 gene are activated by an environmental trigger like a trauma or infection, it increases the activity of protein in the keratinocytes. This skin cell activity increase attracts inflammatory cells to the skin, causing skin cells to mature too quickly and not shed properly. The result is the scaly and flaky layers of skin that characterize plaque psoriasis.

Scientists also found that mutations in the CARD14 could be linked to other types of psoriasis. This is significant since the medical community did not know that different types of psoriasis could be this closely linked. Science Daily notes one of the important discoveries here is that, "Although psoriasis has long been thought to be caused by an overactive immune system, the genetic pathway uncovered by the scientists points to defects in the skin as the main culprit of the condition and to immune cells as secondary players."

The hope is that the more we know about the cause of psoriasis, the closer we get to more effective treatments. And if scientists can isolate how to stop these mutations, one day they may discover a cure.



Sources: "Psoriasis: Who Gets and Causes." American Academy of Dermatology. Web. 2012. "First Gene Linked to Common Form of Psoriasis Identified." Science Daily. Web. April 19, 2012.