Table 1

Meta-analysis of α synuclein/non-amyloid β component precursor allele and genotype distributions in patients with sporadic Parkinson's disease (PD) and controls in Japan

	Allele* frequency						Genotype frequency
Study	−2	−1	0	1	2	3	Allele 1 (+)	Allele 1 (−)
Nomenclature of the alleles according to Xia et al.² Alleles 1, 2, and 3 correspond to alleles 3, 2, and 1, respectively, of Krüger et al.*⁴ pc (corrected p value) was obtained by multiply the p value by the number of alleles. CI, confidence interval; OR, odds ratio.
Present study
PD (n=165)	0.009		0.518	0.255	0.200	0.018	0.358	0.642
Controls (n=155)	0.013		0.406	0.355	0.210	0.016	0.497	0.503
	χ²=9.93, df=4, p=0.042, pc=0.21						χ²=6.3, p=0.012, pc=0.072
Izumi et al³
PD (n=200)		0.003	0.408	0.248	0.330	0.013	0.390	0.610
Controls (n=250)	0.004	0.002	0.390	0.320	0.272	0.012	0.496	0.504
	χ²=8.37, df=5, p=0.14						χ²=5.05, p=0.025, pc=0.15
Combined
PD (n=365)	0.004	0.001	0.458	0.251	0.271	0.015	0.375	0.625
Controls (n=405)	0.007	0.001	0.396	0.333	0.248	0.014	0.496	0.504
	χ²=13.9, df=5, p=0.017, pc=0.099						χ²=11.4, p=0.00073, pc=0.0044 OR 0.61, 95%CI 0.45 to 0.81