Table 2. Candidate genes with a moderate level of epidemiological evidence in lumbar disc degenerationa.
| Gene | Variation | Amount of evidence | ReplicationLevel | ProtectionFrom Bias | Additional biological evidenceb | Ethnicity | Phenotype | Reference |
| ASPN | allele D14 | B | B | B | yes | Japanese Chinese | sciatica and disc signal | Song et al 2008 |
| COL11A1 | rs1676486 | B | B | B | yes | Japanese | sciatica | Mio et al 2007 |
| GDF5 | rs143383 | A | B | A | − | Northern European | X-rayc, partially MRI | Williams et al 2011 |
| SKT | rs16924573 | B | B | A | yes | Japanese Finnish | sciatica | Karasugi et al 2009 |
| THBS2 d | rs9406328 | B | B | B | yes | Japanese | sciatica | Hirose et al 2008 |
| MMP9 d | rs17576 | B | B | B | yes | Japanese | sciatica | Hirose et al 2008 |
a
Based on Venice interim guidelines [33], statistical significance level (p-value) of original association and replication level including also the absence of inconsistent replications. Amount of evidence increases when alleles are contrasted.
b
Reported in the included studies.
c
Combined phenotype of disc space narrowing and presence of osteophytes.
d
One negative replication report [54] in disc signal phenotype.