PURPOSE: Adolescent Idiopathic Scoliosis (AIS) is considered a complex genetic 
disease, in which malfunctioning or dysregulation of one or more genes has been 
proposed to be responsible for the expressed phenotype. However, to date, no 
disease causing genes has been identified and the pathogenesis of AIS remains 
unknown. The aim of this study is, therefore, to identify specific molecules 
with differing expression patterns in AIS compared to healthy individuals.
METHODS: Microarray analysis and quantitative RT-PCR have examined differences 
in the gene transcription profile between primary osteoblasts derived from 
spinal vertebrae of AIS patients and those of healthy individuals.
RESULTS: There are 145 genes differentially expressed in AIS osteoblasts. A 
drastic and significant change has been noted particularly in the expression 
levels of Homeobox genes (HOXB8, HOXB7, HOXA13, HOXA10), ZIC2, FAM101A, COMP and 
PITX1 in AIS compared to controls. Clustering analysis revealed the interaction 
of these genes in biological pathways crucial for bone development, in 
particular in the differentiation of skeletal elements and structural integrity 
of the vertebrae.
CONCLUSIONS: This study reports on the expression of molecules that have not 
been described previously in AIS. We also provide for the first time gene 
interaction pathways in AIS pathogenesis. These genes are involved in various 
bone regulatory and developmental pathways and many of them can be grouped into 
clusters to participate in a particular biological pathway. Further studies can 
be built on our findings to further elucidate the association between different 
biological pathways and the pathogenesis of AIS.