Decreased calcium pump expression in human erythrocytes is connected to a minor haplotype in the ATP2B4 gene

•A minor haplotype in the ATP2B4 gene was found to be associated with significantly reduced PMCA4b levels in the erythrocytes.•Calcium transport measurements show that this haplotype functionally affects the calcium pump in erythrocytes.•This haplotype is in the promoter region of the ATP2B4 gene.•SNPs in this haplotype were previously shown to be linked to reduced MCHC and reducing malaria infection.