Psoriasis is a chronic autoimmune disease that affects more than 8 million people in the United States. In psoriasis, the immune system attacks healthy skin cells, causing them to grow rapidly and form thick, scaly patches on the skin.

While there are several effective treatments available for psoriasis, researchers have been working to better understand the underlying genetic factors that contribute to the condition.

In recent years, scientists have made several new discoveries regarding the genetic markers for psoriasis.

1. HLA Genes are Linked to Psoriasis

One of the most significant discoveries in psoriasis research is the link between certain genes in the human leukocyte antigen (HLA) system and the development of psoriasis.

The HLA system plays a key role in regulating the immune response and is involved in determining whether a person’s body will accept or reject an organ transplant.

Researchers have identified several HLA genes that are associated with an increased risk of developing psoriasis.

For example, one study found that individuals who carried the HLA-Cw6 allele were more likely to develop psoriasis than those who did not carry this gene.

2. Variations in Interleukin Genes Contribute to Psoriasis

Interleukins are a group of proteins that are involved in the immune response. Researchers have identified several variations in interleukin genes that are associated with an increased risk of developing psoriasis.

For example, one common variant is located in the interleukin-23 receptor gene (IL23R) and has been shown to contribute to the development of psoriasis.

3. Mutation in the CARD14 Gene Affects Skin Cell Growth

The CARD14 gene plays a role in regulating the growth of skin cells, and mutations in this gene have been linked to the development of psoriasis.

In 2012, researchers identified a mutation in the CARD14 gene that was associated with the development of psoriasis in several families.

4. Genetic Markers for Psoriasis Vary by Ethnicity

Studies have found that the genetic markers for psoriasis can vary significantly depending on a person’s ethnicity.

For example, a study of Chinese individuals with psoriasis found that variations in the HLA-C gene were more common in this population than in individuals of European descent.

5. MicroRNA Levels are Altered in Psoriasis

MicroRNAs are small RNA molecules that help regulate gene expression. Researchers have found that the levels of specific microRNAs are altered in individuals with psoriasis.

For example, one study found that the level of microRNA-203 was significantly decreased in individuals with psoriasis compared to individuals without the condition.

6. Immune System Dysregulation is a Key Factor in Psoriasis

While genetic factors play a significant role in the development of psoriasis, researchers have also identified several factors related to immune system dysregulation that contribute to the condition.

For example, psoriasis is associated with an increase in certain immune cells, such as T cells and dendritic cells, and higher levels of inflammatory cytokines.

7. Environmental Triggers can Impact Genetic Susceptibility in Psoriasis

While genetics are a major factor in the development of psoriasis, environmental factors can also play a role in triggering the condition.

For example, exposure to certain infections, such as streptococcal bacteria, can increase the risk of developing psoriasis in individuals with a genetic predisposition to the condition.

8. Epigenetic Changes can Impact Gene Expression in Psoriasis

Epigenetic changes are modifications to DNA that can impact gene expression. Researchers have found that epigenetic changes play a role in the development and progression of psoriasis.

For example, one study found that the level of methylation, an epigenetic modification, was significantly reduced in individuals with psoriasis compared to individuals without the condition.

9. New Genetic Markers are Still Being Discovered

While significant progress has been made in identifying genetic markers for psoriasis, researchers are still discovering new genes and genetic variants that contribute to the development of the condition.

A 2019 study identified several new genetic variants that were associated with an increased risk of psoriasis.

10. Genetic Testing can Help Identify Risk of Psoriasis

Genetic testing can help individuals better understand their risk of developing psoriasis. By analyzing an individual’s genetic profile, genetic testing can identify whether they carry any of the known genetic markers for psoriasis.

This information can help individuals take proactive steps to prevent psoriasis or manage the condition more effectively if it develops.