Adolescent idiopathic scoliosis (AIS) is a common disorder with a strong genetic 
predisposition. Associations between AIS and common single nucleotide 
polymorphisms (SNPs) in estrogen receptor genes have been reported. rs9340799 in 
the gene for estrogen receptor α (ESR1) is reported to be associated with curve 
severity in Japanese and with AIS predisposition and curve severity in Chinese. 
In addition, rs1256120 in the gene for estrogen receptor β (ESR2) is reported to 
be associated with AIS predisposition and curve severity in Chinese. However, 
the sample sizes of these previous studies were small, and the associations of 
these SNPs have not been replicated. To examine the association between AIS and 
estrogen receptor genes, we investigated the association of rs9340799 and 
rs1256120 with AIS predisposition and curve severity using a large Japanese 
population, consisting of 798 AIS patients and 637 sex-matched controls. We 
found no association of either SNP with AIS predisposition or curve severity in 
the Japanese population. Considering the statistical power of the present study 
and the limitations of the previous reports, we conclude that the associations 
of rs9340799 and rs1256120 with AIS predisposition and curve severity are 
negative.