Objectives: To study the role of two COL2A1 single nucleotide polymorphisms (rs3737548 and rs2276455) and their haplotypes in individual susceptibility to hand osteoarthritis (OA) in Finnish women.
Methods: Bilateral hand radiographs of 543 Finnish female dentists and teachers aged 45-63 years were examined and classified for the presence of OA by using reference images. The COL2A1 genotypes were determined by PCR-based methods. Data regarding other risk factors were collected by questionnaire. The haplotypes were statistically reconstructed from the genotype data by the PHASE program. Association between the genotypes/diplotypes and hand OA were studied by logistic regression.
Results: Allowing for age and occupation, the carriage of at least one COL2A1 intron 33 minor allele was associated with an increased risk of hand OA (OR=1.58, 95% CI 1.05-2.36) and the number of affected joints. When stratified by occupation, the increased risk associated with the intron 33 minor allele carriage appeared to be mainly attributable to the dentists (OR=2.18, 95% CI 1.18-4.06). The 2-1 haplotype (exon 5B minor allele - intron 33 major allele) posed a significantly higher risk of hand OA (OR=3.21, 95% CI 1.08-9.55) compared with the non-carriers. Moreover, an interaction was observed between the intron 33 minor allele carriage and low task variation history in dental work (OR=2.87, 95% CI 1.05-7.89 for their joint effect).
Conclusions: Our results suggest that the studied COL2A1 gene polymorphisms may play a role in the etiology of hand OA, and that this effect may be enhanced by repetitive loading work tasks.