Monday, March 12, 2012

Genetic Testing of Scoliosis

As we learn more about the genetic basis of scoliosis, the importance of gene testing becomes clearer, both to evaluate family members for potential involvement and to determine the prognosis of curves that have already been detected.

A simple expedient test for scoliosis has been available for about two years and I have used it in my practice with some surprising results.  Curves I thought were at risk clinically were low risk by the test and vice versa.  So far the test has panned out accurately in all cases.

As with all new technology, the use of the test is being challenged by the insurance industry, claiming that it is "unvalidated", "experimental" or an "overpriced screening device".  The following is a letter I wrote to one such insurance company in response to their challenge.  I feel the battle still lies ahead, but this is one circumstance where the effort is well worth it in terms of the peace of mind that the test may afford patients and parents, and the important information that it certainly affords their doctors:

AN OPEN LETTER TO THIRD PARTY INSURANCE COMPANIES

To whom it may concern.

As a pediatric orthopaedic spine specialist, I am extremely concerned by your company's apparent determination to deny payment for the Scoliscore scoliosis gene test.

Let me state that I have no financial interest in Axial Biotech, the company that developed the test, or in Smith & Nephew who distribute it.  I do not personally bill for the test or charge for administering it.  Ordering Scoliscore tests does not in any way benefit me financially.

As a recognized expert in pediatric spinal conditions, I feel strongly that the Scoliscore test is one of the most powerful diagnostic tools that has been developed in recent years.

As you may or may not know, Scoliscore is a salivary test that evaluates the presence of genes that are known to be associated with progression of scoliosis.  On the basis of the number of genes present as well as age of the patient and magnitude of curve, it factors a score from 1 to 200, where 200 is most severe.  In general, the higher the score, the higher risk of progression of the disease.  The test is both highly sensitive and specific.  The positive predictive value of a high score (180 and above) for progression is upwards of 95%.  The negative predictive value of a low score (under 40) is 99%.  As such, it is one of the most accurate prognostic tests available today for any medical condition, and is markedly more accurate than the clinical and radiographic predictors that re currently in use.  The test was prevalidated extensively and is FDA approved.  After two years of widespread availability, it has been validated in clinical use in peer reviewed journals1,2,3.  As such, it is hardly an “experimental test.”

Scoliscore is not a screening test and to my understanding was never intended as such.  There is currently no role for its use in the general population to determine who might someday have scoliosis.  Its indications are strictly to determine risk of progression in growing patients with known mild to moderate scoliosis.  The benefits of accurate prediction of the behavior of scoliosis should be evident and embraced.  If a child is at high risk, early intervention such as appropriate bracing may ultimately spare the need for surgical correction and fusion, with its subsequent risks and problems..  If at low risk, the child will require fewer screening visits and radiographs.  By my estimation, a child of nine with a Scoliscore of 25 may be spared up to 25 or more clinical visits and x-rays over a course of a life time, which represents a huge savings in time, money and, possibly most important, radiation dose.  By this factoring, the Scoliscore test would more than pay for itself.

In two years of using the test personally, I have seen these benefits at both extremes.  I have one young lady, who despite having a relatively small curve (18 degrees at first visit) had a Scoliscore of 193.  By typical clinical pattern, she would have been seen at an interval of six months and reassessed.  Because of the high Scoliscore, I brought her in at two months.  As predicted, she demonstrated rapid progression of the curve and is now in a brace that is containing the scoliosis.  Similarly, I have many children who have scored under 40 despite moderate curves (20-25 degrees) and have been stable enough to put on once yearly surveillance with clinical examination rather than aggressive radiography.

Beyond the immediate clinical benefit, the knowledge that we are obtaining about scoliosis from Scoliscore is of immeasurable value.  Each child will add her story to our collective understanding of the causes of Idiopathic Scoliosis, and may someday lead to a medical understanding of the disorder that may preclude the need for x-rays, braces or even surgery.

Your marketing campaigns have always emphasized your company’s dedication to the patient’s well-being through stressful medical situations, and my and my patient’s experiences have generally borne this out.  However, there is arguably no more continuously stressful circumstance for a young teenager than a spinal deformity.  The peace of mind afforded by accurate and reproducible prognostic information in this setting cannot be underestimated and would seem to fit squarely with your organization’s advertised mission and vision.

I strongly urge you to support the use of Scoliscore and to allow medical coverage of this extremely important modality.

Thank you for your kind consideration.

Sincerely,


Keith P. Mankin, MD FAAP
Raleigh Orthopaedic Clinic
WakeMed Children’s Hospital


1Ward K, Ogilvie JW, Singleton, MS, et al. Validation of DNA-based prognostic testing to predict spinal curve progression in Adolescent Idiopathic Scoliosis. Spine. 2010;35(25):1455-64.

2Ogilvie JW.  Update on prognostic genetic testing in adolescent idiopathic scoliosis (AIS).  Pediatr Orthop. 2011 Jan-Feb;31(1 Suppl):S46-8.
3Ogilvie JW.  Adolescent idiopathic scoliosis and genetic testing. Curr Opin Pediatr. 2010 Feb;22(1):67-70.

No comments:

Post a Comment

Please feel free to comment.