DNA test shows 99% accuracy in predicting curve progression for scoliosis patients

A study published in the Dec. 1 edition of Spine has found that a DNA test used to determine the likelihood of curve progression in children with mild adolescent idiopathic scoliosis is 99% accurate in predicting which children are least likely to progress to a severe curve.

The ScoliScore AIS Prognostic Test (DePuy Spine Inc.), in combination with other radiographic and clinical information obtained at the time of diagnosis, could reportedly help reduce the uncertainty in diagnosing a child with mild adolescent idiopathic scoliosis (AIS) – and reduce the need for repeated physician visits, physical examinations and X-rays.

“This study demonstrates that, for the first time, genetic factors can be used to accurately quantify the risk of scoliosis curve progression,” Kenneth Ward, MD, a co-author of the study, stated in a press release. “Physicians never had this kind of information before. Now that they do, physicians can better personalize treatment plans and provide peace of mind to patients and their families.”

Risk classification

Investigators studied 697 Caucasian patients between 9 and 13 years who had documented mild, moderate or severe AIS. DNA from the patients’ saliva was analyzed using the ScolioScore Test, which produces a score of one to 200 indicating a patient’s individual risk for developing a spinal curve of more than 40°.

A score of 50 or less is classified as low risk, with 51 to 180 being intermediate risk and 181 to 200 being high risk. The score is calculated based on 53 genetic markers previously identified as being associated with scoliosis progression and the patient’s current spinal curve or Cobb angle.

The findings indicate that the test had a 99% accuracy rate in identifying low-risk patients – those least likely to progress to a curve of 40° or more.

Close follow-up still needed

The study authors advised that although the test is accurate for patients who score in the intermediate- or high-risk range, these patients should be followed closely by a specialist as the study was designed to determine negative predictive value rather than likelihood of progression. Furthermore, the results of the test must be interpreted in the context of other clinical and diagnostic information.

The test was developed following review of medical and DNA records of more than 9,500 scoliosis patients and their family members.

Currently, due to a lack of sufficient sample sizes for other groups, the test is offered only to Caucasian children between the ages of 9 and 13 years diagnosed with mild AIS. The study authors noted that other racial groups will be the subject of future studies.

Reference:
Ward K, Ogilvie JW, Singleton MV, et al. Validation of DNA-based prognostic testing to predict spinal curve progression in adolescent idiopathic scoliosis. Spine. 35(25):E1455-E1464. Dec. 1, 2010. doi: 10.1097/BRS.0b013e3181ed2de1.

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