Fig. (2) Correlation between PTPN22 gene C1858T variant genotypes in subgroups of Kuwaiti PsA patients. The Kuwaiti PsA patients group was sub-divided on the basis of age-of-onset of the disease. The arrows indicate distribution of the susceptibility genotypes CT and TT in different age-groups having frequency of 0%, 12.5%, 42%, 33% and 30% respectively. CC, CT and TT are the genotypes of PTPN22 gene [C1858T] functional variant.