Epigenetics in spine curvature disorders

Scoliosis is a three-dimensional (3D) structural deformity of the spine with a radiological lateral Cobb angle of ≥ 10°. Several classification systems exist, dividing different types regarding the age of onset or the type of etiology. The minority of cases are secondary to congenital, syndromic of neuromosucular diseases. Most of the cases are classified “idiopathic” due to unknown etiology. These were formally divided by the age of onset into “Infantile Idiopathic Scoliosis” (0–3 years), “Juvenile Idiopathic Scoliosis” (JIS—4–10 years), and “Adolescent Idiopathic Scoliosis” (AIS → 10 years). Since the initiative of the Scoliosis Research Society in 2014 all kind of scoliosis with the onset before the age of 10 years are classified as “Early-Onset-Scoliosis” (EOS) regardless of the etiology. Further types of scoliosis can occur in the adulthood, which are known as “Adolescent Scoliosis in the Adult” and “Degenerative De-novo Scoliosis” (DS) in the adulthood secondary to degenerative disc diseases and/or in combination with osteoporosis and minor compression fractures. The precise molecular mechanisms underlying idiopathic and de-novo scoliosis are mainly unknown, but recent evidence demonstrate the role of epigenetics in the etiology of these conditions. Importantly, early diagnosis and the accurate prediction of curve progression are of special relevance in clinical settings. Therefore, identifying potential progression-relevant biomarkers can substantially improve the clinical management of these patients. This chapter presents the most relevant epigenetic mechanisms and epigenetic biomarkers, which may favor the implementation of precision medicine in scoliosis treatment.