Table 1. Detailed characteristics of eligible studies considered in the meta-analysis.

First author	Year	Ethnicity	Region	Single-nucleotide polymorphism	Diagnostic criteria	Matching	Source	Method
Ge [16]	2000	Tibetan	Tibet	A-6G	SBP≥140, DBP≥90	Yes	P-B	PCR-RFLP
Hu [14]	2007	Mongolian	Inner Mongolian	A-6G	SBP≥140, DBP≥90	Yes	P-B	Sequencing technique
Jiang [17]	2009	Han	Jiangsu	A-6G, A-20C	SBP≥140, DBP≥90	Yes	P-B	TaqMan - PCR
Kong [15]	2002	Han	Henan	A-6G, A-20C	SBP≥160, DBP≥95	Yes	H-B	PCR-RFLP
Liu [38]	2002	Han	Shanghai	A-6G	SBP≥140, DBP≥90	No	H-B	Sequencing technique
Li [22]	2004	Kazakh	Xinjiang	A-20C	SBP≥140, DBP≥90	Yes1	P-B	PCR-SSCP
Liu [12]	2001	Tibetan	Tibet	A-6G	SBP>140, DBP>90	Yes	P-B	PCR-RFLP
Liu [12]	2001	Yi	Sichuan	A-6G	SBP>140, DBP>90	Yes	P-B	PCR-RFLP
Qi [7]	2008	Han	Beijing	A-6G, A-20C	SBP≥140, DBP≥90	Yes1	P-B	PCR-RFLP
Wang [9]	2002	Amis	Taiwan	A-6G	SBP≥140, DBP≥90	Yes	H-B	Sequencing technique
Wang [18]	2003	Kazakh	Xinjiang	A-6G	SBP≥160, DBP≥95	Yes	P-B	MS-PCR
Wang [11]	2007	Li	Hainan	A-6G, A-20C	SBP≥140, DBP≥90	Yes	H-B	Sequencing technique
Wu [10]	2004	Han	Taiwan	A-6G	SBP≥140, DBP≥90	Yes1	H-B	Sequencing technique
Yang [23]	2000	Tibetan	Tibet	A-20C	SBP≥140, DBP≥90	Yes	P-B	PCR-RFLP
Yao [19]	2010	Bai	Yunnan	A-6G	SBP≥140, DBP≥90	No	H-B	PCR-RFLP
Ying [20]	2010	Mongolian	Inner Mongolian	A-6G, A-20C	SBP≥140, DBP≥90	No	P-B	PCR-RFLP
Yue [21]	2008	Han	Hebei	A-6G, A-20C	SBP≥140, DBP≥90	Yes2	P-B	PCR-RFLP
Liu [24]	2004	Han	Shanghai	A-20C	SBP>140, DBP>90	No	H-B	Sequencing technique

Abbreviations: SBP, systolic blood pressure (mmHg); DBP, diastolic blood pressure (mmHg); P-B, population-based study; H-B, hospital-based study; PCR-RFLP, polymerase chain reaction and restriction fragment length polymorphism; PCR-SSCP, polymerase chain reaction and single strand conformation polymorphism; MS-PCR, mutagenically separated polymerase chain reaction; Yes, age- and gender- matched, Yes¹, gender-matched, Yes², age-matched.