Association of a single nucleotide polymorphism in the insulin-like growth factor-1 receptor gene with spinal disc degeneration in postmenopausal Japanese women

Study Design. An association study investigating the genetic etiology for spinal disc degeneration. Objective. To determine the association of single- nucleotide polymorphism ( SNP) in the insulin- like growth factor- 1 receptor ( IGF1R) with spinal disc degeneration. Summary of Background Data. Insulin- like growth factor-1 ( IGF- 1) signaling pathway is involved in cartilage development and homeostasis, suggesting that genetic variations of genes involved in this pathway may affect the pathogenesis of cartilage- related diseases, such as disc degeneration. Methods. We evaluated the presence of endplate sclerosis, osteophytes, and narrowing of disc spaces in 434 Japanese postmenopausal women. A SNP in the IGF1R gene at intron 1 was determined using TaqMan polymerase chain reaction method. Results. We compared those who carried the G allele ( GG or GC, n = 290) with those who did not ( CC, n = 144). We found that the subjects with the G allele ( GG or GC) were significantly over- represented in the subjects having higher disc narrowing score ( P = 0.0033; odds ratio, 2.04; 95% confidence interval, 1.27 - 3.29 by logistic regression analysis). Conclusion. We suggest that a genetic variation at the IGF1R gene locus is associated with spinal disc degeneration, in line with the involvement of the IGF1R gene in the cartilage metabolism.