Genetic Variants of CHD7 Are Associated with Adolescent Idiopathic Scoliosis

Study Design. A case–control association study. Objectives. The aim of this study was to investigate whether CHD7 was associated with adolescent idiopathic scoliosis in Chinese Han population and to further explore the functional role of CHD7 in the development of adolescent idiopathic scoliosis (AIS). Summary of Background Data. Several studies have explored the association of CHD7 with scoliosis in patients of European descent, while the results were inconsistent. There was a lack of study investigating the association of CHD7 with AIS in Chinese Han population. Methods. Variants within CHD7 were genotyped in 965 AIS patients and 976 healthy controls. Whole exome sequencing was performed in 96 AIS patients. Paraspinal muscles of 43AIS patients and 38 lumbar disc herniation patients were collected for the evaluation of the gene expression. Intergroup comparison was performed with the χ 2 test for genotyping data or Student t test for tissue expression. The relationship of CHD7 expression with clinical phenotypes was determined by the Pearson correlation. Result. Variant rs121434341 of CHD7 was significantly associated with AIS. AIS patients were found to have a remarkable higher frequency of allele G when compared with healthy controls (2.89% vs. 1.57%, P = 0.0018), with an odds ratio value of 1.89. A pathogenic mutation affecting normal splicing was identified in a patient. Moreover, the expression level of CHD7 in AIS patients was significantly lower than in the controls (0.0008437 ± 0.00004583 vs. 0.001129 ± 0.00003773, P < 0.001), and CHD7 expression was positively correlated with bone mineral contents (P = 0.036, r = 0.32). Conclusion. Genetic variants of CHD7 were significantly associated with AIS. Moreover, the decreased expression of CHD7 may be involved in the abnormal bone mass of AIS patients. Further studies are warranted to investigate the functional role of CHD7 in the pathogenesis of AIS. Level of Evidence: 3