A large multicentre analysis of CTGF-945 promoter polymorphism does not confirm association with systemic sclerosis susceptibility or phenotype

Objective: To conduct a replication study to investigate whether the 2945 CTGF genetic variant is associated with systemic sclerosis (SSc) susceptibility or specific SSc phenotype. Methods: The study population comprised 1180 patients with SSc and 1784 healthy controls from seven independent case-control sets of European ancestry (Spanish, French, Dutch, German, British, Swedish and North American). The 2945 CTGF genetic variant was genotyped using a Taqman 59 allelic discrimination assay. Results: An independent association study showed in all the case-control cohorts no association of the CTGF 2945 polymorphism with SSc susceptibility. These findings were confirmed by a meta-analysis giving a pooled OR=1.12 (95% CI 0.99 to 1.25), p=0.06. Investigation of the possible contribution of the 2945 CTGF genetic variant to SSc phenotype showed that stratification according to SSc subtypes (limited or diffuse), selective autoantibodies (anti-topoisomerase I or anticentromere) or pulmonary involvement reached no statistically significant skewing. Conclusion: The results do not confirm previous findings and suggest that the CTGF 2945 promoter polymorphism does not play a major role in SSc susceptibility or clinical phenotype.