Scoliosis has been known to run in families. According to the University of Iowa Health Care department, “Hereditary and congenital irregularities have emerged as the most probable causes of scoliosis today.” While genetics is believed to play a role in scoliosis and despite the vast amount of research, more than 80 percent of scoliosis cases are deemed idiopathic, meaning the source of the condition is unknown. The cause of Adolescent Idiopathic scoliosis remains unknown. It is possible scoliosis is inherited from a parent the way other genetic traits are passed down from parent to child. This theory is greatly supported by the tendency for scoliosis to run in families as seen with parent, child and siblings. Studies have shown that the incidence of scoliosis in these cases ranges from 7-11%. In contrast, the incidence in grandparent, grandchild, uncle, aunt, nephew, niece, or half-sibling drops to less than 4%.
In 2007, Texas Scottish Rite Hospital for Children researchers identified the first gene – CHD7 – associated with idiopathic scoliosis. It was the result of a 10-year study, led by Carol Wise, Ph.D., conducted at the Sarah M. and Charles E. Seay/Martha and Pat Beard Center for Excellence in Spine Research. In 2011, they identified two additional genes – CHL1 and DSCAM – which play a role in the neurological and spinal systems. These findings will allow for new hypotheses for the etiology of scoliosis and serve as a tool for further research.
Genetic research behind the ScoliScore AIS Prognostic Test began in 2003. Researchers explored the entire human genome searching for genes that were linked to Scoliosis. DNA samples from over 9,000 patients from 85 clinics worldwide were analyzed. The researchers identified 53 genetic markers (or mistakes in the DNA) that are linked to AIS. Researchers identified 28 signs in DNA that an AIS curve will progress (progressive genes), and 25 signs in DNA that an AIS curve will not progress (protective genes).
ScoliScore AIS Prognostic Test was made available in 2009 as a genetic test. It was used analyze the DNA of male and female patients diagnosed with Mild (10–25° Cobb angle) Adolescent Idiopathic Scoliosis (AIS) who are between 9 to 13 years of age and who are self-reported as Caucasian (including patients of North American, South American, European, Eastern European, Middle Eastern, or South West Asian descent). As of 2016, the test is no longer available. Read More....
Dr. Alain Moreau, PhD, head of the molecular genetics lab for musculoskeletal diseases at the Ste-Justine University Hospital Centre, Montréal, Canada said in an interview:
“Most likely, scoliosis is not a purely genetic disease. Although genetic factors are important, a “cross talk” between genetics and some environmental factors is evident. The nature of these environmental factors, however, is unclear. The underlying genetic defects may be present at birth, but because the clinical manifestations usually occur at adolescence or prepubescence, scoliotic deformities must be triggered by environmental factors, which also include hormonal changes associated with puberty. Increased levels of estrogen at puberty could explain why girls are more affected in number and severity than boys. Blood tests can now identify children at risk of developing scoliosis. We need to do more work on phenotype and trying to make sense of that and correlating it to genotype.”
So while genes may play a key role, like other genetic conditions, environmental factors may influence or even bring out this genetic predisposition.
Increased genetic research and discoveries will allow for greater insight into what causes scoliosis and more specifically what may cause idiopathic scoliosis. Genetic research may be the answer for what causes scoliosis but it may also lead to improved scoliosis prevention and treatment for scoliosis.