Recent advances in the treatment of scoliosis in children

Genetics Adolescent idiopathic scoliosis (AIS) has been shown in both clinical and genetic studies to have a genetic component to its aetiology,1-8 although the pattern of inheritance still remains elusive; X-linked dominant,3 autosomal dominant or multifactorial patterns1,2,7 have all been suggested. Genealogy work with a cohort of 145 patients with AIS demonstrated a 97% connectedness to other families with AIS, with differences in both expressivity and penetrance, suggesting that there is more than one gene responsible for AIS.9 Work using genome-wide scanning continues to support this hypothesis by identifying specific areas on the human genome which are potentially significant in the aetiology.7 Miller et al,6 in one study of 1198 individuals in 202 families, reported linkage to loci on chromosomes 6p, 6q, 9q, 16q, 17p and 17q. This followed work by Wise et al,10 who identified loci on chromosomes 6p, 10q and 18q in one polygeneration family and Chan et al,11 who reported loci on chromosomes 19p and 2q. Predicting the risk of curve progression has also been the focus of genome studies. Braun et al12 identified 12 DNA markers as having diagnostic utility in AIS. When compared with standard radiological methods, these markers provided a superior assessment of risk of progression. Further development of this work has led to the ‘Scoliscore AIS prognostic test’ becoming available to spine specialists in the US in 2009.13 This salivabased genetic test uses 53 DNA markers which have been linked to the progressive form of scoliosis. Validation work by the development company, Axial Biotech, quotes a 99% negative predictive value (95% confidence interval (CI) 96% to 100%) but independent validation is awaited.