CLEC4M and von Willebrand disease 1: Assuming that this amino acid change may somehow alter the function of the ligand binding domain of the CLEC4M protein, resulting in a higher affinity for and more efficient binding of VWF molecules in the bloodstream, the increased allele frequency in the type 1 VWD population relative to the control populations (4.9%) was compatible with an explanation model where rs2277998 contributes to type 1 VWD.