TIR-domain-containing Adaptor Protein Gene TIRAP S180L Polymorphism is Not Increased in Behçet's Disease Patients in Two Ethnic Cohorts

Objectives: The single nucleotide polymorphism (SNP) of TIRAP (Serine 180 leucine, S180L) that is shown to be associated with Behçet's disease (BD) in a European-derived cohort, but not in Middle Eastern patients is investigated in two other populations.

Methods: Two cohorts of BD patients and controls from Turkey (n=797) and Italy (n=633) were genotyped by sequence specific primer-polymerase chain reaction (SSP-PCR) or TaqMan q-PCR assays.

Results: Genotype and allele frequencies in TIRAP S180L (rs8177374) were not different between BD patients and controls in either ethnicity. Furthermore, a meta-analysis between the Turkish and the Italian BD cohorts did not reveal an association between this non-synonymous SNP in TIRAP and BD (meta-analysis OR=0.94, meta-analysis p=0.61, Q statistic heterogeneity p=0.11).

Conclusions: TIRAP S180L gene polymorphism, which was previously shown to be associated with BD in a Caucasian population, has been replicated in either Turkish or Italian population in our study.