OBJECTIVETo identify whether SH3GL1 gene serves as a disease associated gene of adolescent idiopathic scoliosis (AIS).

METHODSPositioning candidate cloning: "case-sibling or case-family control design" research scheme based on family constellation was designed. Fifty-six AIS patients (15 male and 41 female, mean age 15 years old, ranged from 8 to 22 years old, Cobb angle from 25 degrees to 110 degrees , average Cobb angle of 67.5 degrees ) from November 2007 to December 2008 were recruited. In all patients, blood preparation was collected, and genome DNA was extracted. According to nucleotide sequence of gene SH3GL1, primer pair for PCR amplification, cloning, and sequencing with 10 exons as emphasis was designed. Sequence comparative analysis for exon sequencing result between sib pairs or family pairs, and that between sib pair or family pairs and NCBI (National Center for Biotechnology Information) were conducted through Vector NTI Advance 10.3 software to judge whether basic group mutation occurred or not. Amino acid sequence comparative analysis for prediction was made.

RESULTSTen exons of the candidate gene SH3GL1 were successfully amplified and cloned in genome DNA of an AIS sib pair and family pairs, and the sequencing obtained positive results. Twelve basic group mutations were found in 10 exons of the candidate gene SH3GL1 of patients with AIS. These mutations were located in the second exon (3 mutations), the fourth exon (1 mutations), the fifth exon (4 mutations), the sixth exon (1 mutations), the eighth exon (1 mutations), and the tenth exon (2 mutations, noncoding region). If basic group in 515 of mRNA was mutated to T, termination codon(TAG) came into being and open reading frame was altered. The sequence of protein showed brachytmema protein was encoded, which could cause changes of primary structure.

CONCLUSIONSH3GL1 is possibly one of the disease associated genes of AIS.