Rosacea – HLA-DQA1, HLA-DQB1, HLA-DRB1, GSTM1 and GSTT1 genes.


Rosacea, also known as granulomatous rosacea, ocular rosacea or papulopustular rosacea, is a chronic skin disease that affects the face, mainly the forehead, nose, cheeks and chin.

Three types of rosacea have been described, categorized by their primary signs and symptoms: erythematotelangiectatic rosacea, which results in dry skin, redness and telangiectasia; papulopustular rosacea, which results in reddening of the skin, swelling and pustules; and fimatose rosacea, which is characterized by hypertrophy and thickening of the skin, making it irregular. People with rosacea may feel itching or burning in the affected areas. Frequently, this process affects the eyes, which causes abnormal inflammation of the eyelids and eyes. This inflammation can lead to dryness, redness and irritation of the eyes and can affect vision.

Rosacea is probably due to a combination of genetic and environmental factors, although many of these factors have not been identified. It is believed that rosacea is associated with abnormalities of the vascular system and the immune system. In people with this condition, blood vessels dilate too easily, which can cause redness and abnormal inflammation of the skin. 

Among the genes that are believed to play a role in rosacea are several genes of the human leukocyte antigen (HLA) complex family. These include the HLA-DQA1 genes (major histocompatibility complex, class II, DQ alpha 1), HLA-DQB1 (major histocompatibility complex, class II, DQ beta 1) and HLA-DRB1 (major histocompatibility complex, class II, DR beta 1), located on the short arm of chromosome 6 (6p21.32). The HLA complex helps the immune system to distinguish the body's own proteins from the proteins created by foreign invaders. Each HLA gene has many different variants, which allows each person's immune system to react to a wide range of foreign proteins. Certain variants in the HLA genes probably contribute to the abnormal inflammation characteristic of rosacea.

Another group of genes that seem to be involved in the development of rosacea are the genes of the family glutathione S-transferase (GST), in particular the gene GSTM1 (glutathione S-transferase mu 1), located on the short arm of chromosome 1 (1p13.3) and the GSTT1 gene (glutathione S-transferase theta 1), located on the long arm of chromosome 22 (22q11.23). The proteins encoded from these genes help protect cells from oxidative stress. Variants in several GST genes have been associated with an increased risk of developing rosacea. It is believed that these variants reduce the ability of GST to protect skin cells from oxidative stress, leading to cell damage and inflammation.

In addition to genetic factors, environmental factors can also increase the risk of developing rosacea and trigger its symptoms. Among the best-studied risk factors for rosacea is exposure to ultraviolet (UV) radiation from the sun. In addition, excessive growth of certain microorganisms that live on the skin of the face, particularly mites known as Demodex folliculorum, can also contribute to the development of rosacea. These mites stimulate an abnormal immune response and degrade the normal skin barrier. Other factors that can trigger the signs and symptoms of rosacea or make them worse are exposure to heat, spicy foods, cigarette smoking and alcohol.

The inheritance pattern of rosacea is complex because it is due, in most cases, to a combination of genetic and environmental factors. Studies suggest that people with rosacea are four times more likely to have a family history of the process than people without the disease. This increased risk is probably due to shared genetic factors, but it can also be related to the environment and other non-genetic factors shared by members of a family.

Tests performed in IVAMI: in IVAMI perform the detection of mutations associated with rosacea, by complete PCR amplification of the exons of the HLA-DQA1, HLA-DQB1, HLA-DRB1, GSTM1 and GSTT1 genes, respectively, and its subsequent sequencing

Recommended samples: blood extracted with EDTA for separation of blood leukocytes, or card impregnated with dried blood sample (IVAMI can mail the card to deposit the blood sample).