COL4A3 and Alport syndrome: The COL4A3/COL4A4 heterozygous variants were also reported to cause autosomal dominant Alport syndrome (ADAS, OMIM 104200) (Boye et al., 1998), while homozygous or compound heterozygous variants were responsible for the autosomal recessive Alport syndrome (ARAS) (Longo et al., 2002; Voskarides et al., 2007).