Clinical studies have shown distinct differences in later-onset idiopathic scoliosis (IS) between men and women, including curve severity, stiffness, and ease of operative intervention. Therefore, significant scoliosis in men was used as criteria to create a phenotypical subset of families with IS. The goal of this study is to identify genetic determinants that relate specifically to men with a scoliotic curvature of 30° or more. We identified 25 families (208 individuals) in which a male was diagnosed with 30° or more IS curvature in adolescence. 123 individuals were affected (48 male; 75 female), and 85 were unaffected (45 male; 40 female). Initially, a genomic screen was done with a modified CHLC (version 9) marker set. After initial linkage analyses, the group underwent finemapping with a custom single-nucleotide polymorphism (SNP) panel and ABI Taqman methodology on an ABI 377 platform. The initial genome-wide screen and subsequent analyses were analysed by model-independent linkage analysis with SIBPAL (SAGE, version 5).Introduction
Methods
We reviewed 31 consecutive patients with Friedreich’s
ataxia and scoliosis. There were 24 males and seven females with
a mean age at presentation of 15.5 years (8.6 to 30.8) and a mean
curve of 51° (13° to 140°). A total of 12 patients had thoracic
curvatures, 11 had thoracolumbar and eight had double thoracic/lumbar.
Two patients had long thoracolumbar collapsing scoliosis with pelvic
obliquity and four had hyperkyphosis. Left-sided thoracic curves in
nine patients (45%) and increased thoracic kyphosis differentiated
these deformities from adolescent idiopathic scoliosis. There were
17 patients who underwent a posterior instrumented spinal fusion
at mean age of 13.35 years, which achieved and maintained good correction
of the deformity. Post-operative complications included one death due
to cardiorespiratory failure, one revision to address nonunion and
four patients with proximal junctional kyphosis who did not need
extension of the fusion. There were no neurological complications
and no wound infections. The rate of progression of the scoliosis
in children kept under simple observation and those treated with bracing
was less for lumbar curves during bracing and similar for thoracic
curves. The scoliosis progressed in seven of nine children initially
treated with a brace who later required surgery. Two patients presented
after skeletal maturity with balanced curves not requiring correction.
Three patients with severe deformities who would benefit from corrective
surgery had significant cardiac co-morbidities.