The IFITM3 rs12252 variant was associated with respiratory infection hospitalization but not specifically in patients infected with Influenza A(H1N1)pdm09.
Several studies suggest that the CC genotype at the single nucleotide polymorphism (SNP) rs12252 of IFITM3 confers a genetic predisposition to pandemic influenza A in Europeans and Han Chinese, although one study in a British cohort failed to show an association.