ABCC6 and Pseudoxanthoma elasticum: The chromosome 21q22.11 locus prioritized genes include multidrug resistance protein-6 (MRP6), also known as ATP-binding cassette subfamily C, member 6, or ABCC6, which encodes for a cellular transporter, and pathogenic variants inherited in a recessive pattern have been described to cause pseudoxanthoma elasticum, a connective tissue disorder with characteristic arterial dysplasia characterized by calcification in elastic tissues.