ALG1 and schizophrenia: Based on the age-at-onset stratification analysis, three of the WDR3 SNPs [W4 (rs319471), W8 (rs1321663) and W12 (rs10802003)] and four of the ALG1 SNPs [A1 (rs8053916), A5 (rs3760029), A6 (rs3760027) and A9 (rs7195893)] displayed a tendency to correlation with the different onset age groups of schizophrenia, although it was not significant after multiple testing (S1 Table).