Lumbar degenerative disc disease: all in the genes?

Back pain is the second most common reason for patients to seek medical care in the USA [1]. Low back pain is estimated to occur in up to 84% of individuals at some point in their life, and lumbar disc degeneration is one of the most common findings in the work-up of low back pain [2]. Owing to its prevalence, it is not surprising that the diagnosis and treatment of low back pain has a large socioeconomic impact. The total cost of back pain, including lost wages and reduced productivity, is estimated to exceed 100 billion dollars per year in the USA [3]. This staggering societal cost is paralleled by the individual patient’s burden of pain, disability and psychological distress. This enormous impact underscores the importance of developing improved methods to prevent, diagnose and treat these disorders. With lumbar disc degeneration, herniation of the disc can occur leading to leg pain or neurogenic symptoms, in addition to back pain. The term lumbar degenerative disc disease (LDD) lacks a standard definition, but includes the entire spectrum of disease from disc desiccation (‘black disc disease’) to osteophyte formation or frank disc herniation. Despite its prevalence, the etiology of LDD is incompletely understood. In many situations, the sole presence of degenerative disc disease may or may not correlate with low back pain symptoms. Studies have suggested a multifactorial etiology including contributions from mechanical stresses [4,5], nutritional factors [6], age-dependent disc degeneration [7], biochemical factors [8] and genetics [9,10]. In this article, we hope to dissect the available data to evaluate the current understanding of the causes of LDD and low back pain.