Copy number variations in the two ABCC6 pseudogenes ABCC6Ψ1 and ABCC6Ψ2 [116, 117] have been found to be more common in PXE patients than in controls, although the clinical significance of this, if any, is unclear [118, 119]. This evidence concerns the gene ABCC6 and autosomal recessive inherited pseudoxanthoma elasticum.