Table I.

Characteristics of case-control studies included in meta-analysis

Author	Year	Country	Ethnicity	Age group	Gender	Case (n)	Control (n)	Genotyping method
Wang	2009	China	Asian	Child	Mix	931	1027	PCR-RFLP
Chen	2010	China	Asian	Child	Mix	168	205	PCR-RFLP
Wei	2011	China	Asian	Child	Mix	186	198	PCR-RFLP
Wang	2011	China	Asian	Child	Mix	287	217	PCR-LDR
Luo	2013	China	Asian	Adult	Mix	103	48	RT-PCR
Maalmi	2014	Tunisia	African	Child	Mix	171	171	PCR-RFLP
Narbutt	2014	Poland	Caucasian	Child	Mix	166	166	PCR-RFLP
Zeng	2015	China	Asian	Child	Mix	224	150	PCR-RFLP
Du	2016	China	Asian	Adult	Mix	125	132	PCR-RFLP
Resende	2016	Portugal	African	Adult	Mix	192	149	RT-PCR