Males with familial idiopathic scoliosis: a distinct phenotypic subgroup.

Study Design: Statistical analysis of genomic screening and fine mapping data.

Objective: The goals of this study were to analyze a region on chromosome 17 and to identify specific genetic determinants within this region linked to familial idiopathic scoliosis (FIS) in a subgroup of families in which affected males have undergone surgery.

Summary Of Background Data: The high prevalence and variability of FIS is indicative of genetic heterogeneity. To localize genes related to scoliosis, identification of groups of families with common clinical characteristics is a strategy that reduces genetic heterogeneity. Two independent studies have implicated a region on chromosome 17 as related to FIS.

Methods: With approval of the Institutional Review Board, the initial study population consisted of 202 families (1198 individuals), each of which had 2 or more affected individuals; 17 of those families had an affected male who had surgery. Individuals underwent genomic screening and subsequent fine mapping. Results were obtained using model-independent linkage analysis, with scoliosis set as a qualitative and as a quantitative trait, as implemented in SIBPAL (S.A.G.E., v4.5). The level of significance was set at P < or = 0.05.

Results: The initial study population had significant results at markers d17s975 and d17s2196. Analyses of a subgroup of families with males having undergone surgery using a customized single nucleotide polymorphism panel resulted in increased significance of this region.

Conclusion: The data confirm a previously reported genetic locus on chromosome 17 as statistically significant in the etiology of FIS within a subgroup of families in which an affected male had spinal surgery.