Table 1. The characteristics of six selected studies in this meta-analysis.

Study	Population	Cases	Controls	Genotyping platform
Jiao 2015 [42]	Chinese	229	318	ABI 3730xl sequencer
Liu 2012 [30]	Chinese	571	607	ABI3130XL sequencer
Ohara 2012 [33]	Japanese	825	2933	Multiplex PCR-based Invader assay
Miyashita 2013 [43]	Japanese	891	844	Affymetrix GeneChip 6.0 and TaqMan
Miyashita 2013 [43]	Korean	339	1,129	Affymetrix GeneChip 6.0 and TaqMan
Lambert 2013 [32]	European	17,008	37,154	Imputation