Genetics of Psoriasis - Short Resume
Psoriasis is a disease with a genetic background (4). Several psoriasis susceptibility loci (PSORS) have been found on various chromosomes: PSORS1 on 6p21.3, PSORS2 on 17q, PSORS3 on 4q, PSORS4 on 1q21, PSORS5 on 3q21, PSORS6 on 19p, PSORS7 on 1p, PSORS8 on 16q, PSORS9 on 4q31, PSORS10 on 18p11, PSORS11 on 5q31-q33 and PSORS12 on 20q13. (27). However, the exact genes and their functions, or their respective malfunctions, in psoriasis and arthritis have not been unambiguously identified. Recently, it has been argued that PSORS1 may indeed be the HLA-Cw*06 allele encoding the HLA-Cw6 molecule (35).
Psoriasis is a chronic inflammatory disease of skin that also often affects joints and nails. This disorder is characterized by hyperproliferation of keratinocytes, activation of angiogenesis, vasodilatation and mainly by lymphocyte infiltration of dermis and epidermis (45). The process of maturation of keratinocytes is accelerated and thus not quite terminated. Psoriatic lesion appears on skin.
Skin manifestations are typically red bounded areas of different size and shape with characteristic silvery scales (9). Lesions appear mostly on the skin of elbows and knees, scalp including genitals. Individual manifestations differ in size and severity from localized lesions to whole body involvement. Very often psoriasis affects nails of hands and feet. It can also cause inflammatory changes on joints, named as psoriatic arthritis. Similarly to rheumatoid arthritis and sclerosis multiplex, psoriasis is classified as an immune mediated inflammatory disorder. Those disorders are characterized by chronic progression of an inflammatory process and important role of TNF alpha. Because of the role of TNF alpha in pathogenesis, we can use its inhibitors in therapy. It also affects progress of different comorbidities such as diabetes mellitus 2 and cardiovascular problems (21). Patients with psoriasis have often other risk factors for atherosclerosis such as lipid metabolism disorders and overweight (37).