Intervertebral disc degeneration (IDD) presents a global burden in ageing populations. While the etiology of IDD is not fully understood, ageing is definitely a contributing factor, and genetics play a significant role influencing onset, progression and severity. In addition, there are many other confounding factors including occupation, life style and diet. Thus, to truly understanding the cause of IDD is an enormous task, as with studies of other complex diseases. Genetics has the power to provide insights into cause and disease mechanism, as well as means to provide diagnostic and prognostic assessment if we have the appropriate information. These are the goals of genetic studies in IDD.
Current genomic technologies allow the rapid and affordable assessment of genetic materials to study whole genome variations, and the algorithms to make sense of these variations in relation to the disease outcomes. However, the key for a thorough interrogation of the genomic information lies in the size of the cohort and the accuracy of the phenotypic assessment; that is, what is the definition of IDD. As the intervertebral disc (IVD) is a complex structure, we must tease apart the contribution from each of the components as well as the sum of the components. Further, in our assessment of the MRI of the lumbar disc, there is evident to support degenerative outcomes that are age-dependent and age-independent, and the age-independent association may relate to the original development of the spine, linked to disease outcomes later in life.
Together, a clear understanding and assessment of the IDD phenotype will provide the power needed in genetic studies of IDD for insights into the disease mechanism and thus treatment and prevention.