Kyphoscoliosis is defined by a structural lateral curvature of the spine of 10° or more and an excessive thoracic kyphotic curve of 40° or more. Genetic analyses of families in which two or more members had kyphoscoliosis identified a 3·5 Mb area on chromosome 5p containing three genes of the Iroquois (IRX) homeobox family, Exons and highly conserved non-coding regions (HNCRs) 500 kb upstream and downstream fromIntroduction
Methods
Idiopathic scoliosis (IS) has been associated with several genetic loci in varying study populations, reflecting the disorder's genetic complexity. One region of interest is on chromosome 17, flanking regions linked to neurofibromatosis type 1 (NF1). This region is of particular relevance because the most common osseous manifestation in NF1 is scoliosis (10–30% of patients). This alludes to a potential genetic correlation within this region affecting spinal development or stability. The objective of this research is to identify candidate genes within this region that are statistically linked to IS. An initial population of IS families recruited through approval by the institutional review board (202 families; 1198 individuals) had DNA harvested from blood, and underwent genomic screening, finemapping, and statistical analyses. We identified a specific familial subset: families with males having undergone surgery for scoliosis (17 families, 147 individuals). The initial genome-wide scan indicated that this subset was linked to chromosome 17q.11.2. The most prominent marker, D17s975, (p=0·0003) at 25.12 Mb is adjacent to the NF1 deletional region. We then analysed a custom panel of single-nucleotide polymorphisms (SNPs) extending from 18·30–31·47 Mb for linkage through Taqman SNP assay protocol. With allele specific fluorescent tags, allelic discrimination was done with real-time PCR.Introduction
Methods