An investigation of the relationship between serotonin transporter gene promoter polymorphism and psoriasis susceptibility in a Thai population.

The serotonin transporter (5-HTT) is of great significance in the control of the serotonergic system, and its expression is known to be upregulated in psoriasis, a chronic or recurrent inflammatory skin disease. We investigated a possible association between the 5-HTT gene-linked polymorphic region (5-HTTLPR) and psoriasis in a Thai population. One hundred and fifty-six psoriatic patients and 156 unrelated healthy controls from Bangkok were genotyped using PCR. We found no overall differences in genotype distributions or allele frequencies between the two groups. In addition, when subgroups of psoriatic patients classified by either onset or severity were analyzed, no significant association between this polymorphism and any subgroup was observed. We conclude that 5-HTTLPR is not associated with susceptibility to psoriasis in this Thai population.