Common variants of COL4A1/A2 are associated with sporadic deep intracerebral hemorrhage (ICH) in Caucasians, but the role of these variants in Chinese Han population remains unknown. We intended to explore the association between reported and tag single nucleotide polymorphims  (SNPs) of COL4A1/A2 and ICH in Chinese Han populations. 
By screening 7,029 patients for eligibility, we recruited 812 ICH patients as well as 822 control subjects. Twelve common variations in COL4A1/A2, including 3 intronic SNPs that were reported to be associated with ICH in Caucasians, 5 tag SNPs in COL4A1 and 4 tag SNPs in COL4A2 were genotyped. Multivariate logistic regression was used to detect the association between directly genotyped SNPs and ICH. 
The homozygous of risk allele (T) of an unreported SNP- rs1556122 increased risk of ICH (OR=1.41, 95% Confidence Interval[1.08-1.84], P=0.01) . High linkage disequilibrium was observed between rs1556122 and one of the reported intronic SNPs-rs9515199 (r2=0.869, D’=0.97). 
We  performed the first exploration of the association between common variations of COL4A1/A2 and risk of ICH in Chinese Han population. Risk allele of a SNP-rs1556122 that not reported previously increased ICH risk. The lead SNP in our study was in high linkage disequilibrium with a reported intronic SNP-rs9515199, and may indicate a potential function-regulating locus for COL4A1/A2 gene .

Variation at rs1556122 in COL4A1/A2 increases risk of intracerebral hemorrhage in Chinese Population