Background and methods: Adolescent idiopathic scoliosis (AIS) is the most common spinal deformity in children, with a prevalence of 1–2%. The disease generally displays complex inheritance. Various family studies have produced many first reports of AIS susceptibility regions, but confirmation of these is lacking. In the present study we investigated extension of our own data, and reproducibility of other published results, by testing linkage in a new collection of fifty-four AIS families. Altogether fifteen candidate regions were evaluated in a two-stage design.

Results: Strongest results were obtained for linkage to microsatellite loci within a candidate region of proximal 8q previously identified by chromosomal breakpoint mapping. Although positive lod scores were obtained for other regions, none exhibited significance less than or equal to P = .05. Lod scores remained stable after analysis of an independent panel of SNP loci in the 8q candidate region and were strengthened with inclusion of additional affected family members (multipoint NPL = 3.02, P = 0.001). Two SNPs near the peak of linkage produced evidence of association to AIS susceptibility. Both SNPs are found within plausible candidate genes for AIS susceptibility.

Conclusion: These results support linkage of the 8q11-8q13 region to AIS susceptibility. Bashiardes et al. previously described a chromosomal break in the 8q11 region that disrupted the gamma-1- syntrophin (SNTG1) gene and segregated with AIS in an extended kindred. In that study, possible rare splice site mutations were identified an additional affected family and one sporadic case. The peak of linkage and association detected in this study appears to be distinct from the SNTG1 gene. This suggests the possibility that more than one gene in the region may contribute to disease. A more detailed analysis of the region encompassing this linkage peak, and the SNTG1 gene, is warranted in larger family collections.