The Protein Tyrosine Phosphatase Nonreceptor 22 () R620W Functional Polymorphism in Psoriasis.

BACKGROUND

Psoriasis is a complex autoimmune disease caused by the interaction of genetic and environmental factors. gene polymorphism has been reported to affect psoriasis susceptibility; however, no data are available for Middle Eastern populations.

OBJECTIVE

The aim of this study was to investigate the association of PTPN22 (1858C/T) R620W polymorphism with psoriasis in a Saudi cohort.

METHODS

Saudi subjects (n = 306) including patients with psoriasis (n = 106) and matched controls (n = 200) were studied for variants using tetra-primer amplification refractory mutation system-polymerase chain reaction method. The frequencies of alleles and genotypes of PTPN22 (1858C/T) polymorphism were compared between patients and controls.

RESULTS

The frequency of CT genotype of PTPN22 (1858C/T) polymorphism was significantly higher, whereas that of CC genotype was lower in patients with psoriasis than in controls (< .001, relative risk [RR] = 7.151). The homozygous genotype TT was absent in both the patients and healthy controls. The frequency of allele T encoding tryptophan (W) was significantly increased (< .001, RR = 5.76), whereas that of allele C encoding arginine (R) decreased in psoriasis cases as compared with controls (< .001, RR = 0.173) indicating that individuals carrying allele T are more susceptible to psoriasis than noncarriers.

CONCLUSIONS

PTPN22 (1858C/T) polymorphism is positively associated with susceptibility of psoriasis in Saudis and can be developed as biomarker for evaluating psoriasis risk. However, further studies on PTPN22 polymorphism in larger samples from different geographical areas and ethnicity are warranted.