Deguchi T, et al. - Via a cross-sectional study of 1,605 people, the experts intended to interpret the genetic mechanisms underlying intervertebral disc degeneration (IDD) and to investigate the associations of single-nucleotide polymorphisms to IDD in a general population in Japan. Through the Pfirrmann’s scoring system, C2-3 to L5/S1 in the total spine MRI were assessed. At the T12-L1 disc level, the maximum odds ratio was observed for rs9406328 in the THBS2 gene. In comparison to those with 0 or 1 risk allele, the average IDD score who had 2 risk alleles of rs9406328 was considerably higher among people who were aged <50 years and 50-59, with a much broader difference than the elderly participants. Therefore, in the younger age groups, the genetic effect of rs9406328 was more potent. Statistical interaction between age and the number of risk alleles at C7-T1, T3-4, and T4-T5, as well as T12-L1, was exhibited by multiple linear regression analyses of the correlation between rs9406328 and IDD, adjusted for age, sex, and BMI at each disc level. Hence, replication of the association between rs9406328 in THBS2 and IDD was observed. Further, the difference by disc level of the contributions of genetic and environmental factors to IDD was recognized.