Table 1.
Characteristics of the included studies.
| Study | Allele designations and frequencies | Case confirmation | Match criteria for controls | No. of cases/controls (values of H-W in controls) | Quality assessments | Reference |
|---|---|---|---|---|---|---|
| Ding et al.6 | rs2383206 First stage: (A→G, P = 0.164) Second stage: (A→G, P = 0.051) rs10757278 (A→G, P = 0.249) Second stage: (A→G, P = 0.030) |
NE, CT, or MRI according to ICD-9 criteria | Ethnicity and resident area | First stage: 551/556 (0.252) Second stage: 440/498 (0.122) First stage: 558/554 (0.204) Second stage: 441/501 (0.102) |
6 | 6 |
| Hu et al.7 | rs2383206 (A→G, P = 0.062) rs10757274 (A→G, P = 0.181) |
CT and/or MRI | Sex and ethnicity | 352/423 (0.169) 353/430 (0.579) |
5 | 7 |
| Zhang et al.10 | rs2383206 (A→G, P = 0.010) rs2383207 (G→A, P = 0.180) rs10757274 (A→G, P = 0.001) rs10757278 (A→G, P = 0.002) |
NE, CT or MRI according to WHO criteria | Age, sex, ethnicity, and resident area | 1190/1664 (0.529) 1190/1664 (0.266) 1190/1664 (0.376) 1190/1664 (0.999) |
9 | 10 |
| Yue et al.8 | rs2383206 (A→G, P = 0.500, adjusted P = 0.610) rs2383207 (G→A, P = 0.040, adjusted P = 0.030) rs10757274 (A→G, P = 0.880, adjusted P = 0.950) rs10757278 (A→G, P = 0.870, adjusted P = 0.950) |
CT or MRI | Age, sex, and ethnicity | 766/680 (0.429) 767/682 (0.504) 769/682 (0.909) 769/680 (0.831) |
7 | 8 |
| Xiong et al.9 | rs2383206 (A→G, P = 0.636) rs10757274 (A→G, P = 0.449) |
According to WHO criteria | Age, sex, and ethnicity | 200/205 (0.579) 200/205 (0.403) |
7 | 9 |
| Lin et al.11 | rs2383207 (G→A, P = 0.057, adjusted P = 0.097) |
CT or MRI according to WHO criteria | Ethnicity | 627/1349 (0.660) | 6 | 11 |
| Bi et al.12 | rs10757278 (A→G, P = 0.003) |
NE, CT, or MRI according to ICD-9 criteria | Age, sex, and ethnicity | 116/118 (0.307) | 7 | 12 |
NE: neurological examination; CT: computed tomography; MRI: magnetic resonance imaging; ICD-9 criteria: International Classification of Diseases (9th revision); H-W: Hardy–Weinberg equilibrium; WHO: World Health Organization.
Quality assessment was done according to Newcastle–Ottawa Scale; 5/9 was thought to be an eligible score for quality assessments.