Regarding the genetic diagnosis of Alport syndrome, 7 (PT479, PT687, PT788, PT1098, PT1226, PT1244, and PT1330; 20.0%) had hemizygous variants in COL4A5, 1 (PT1198; 2.9%) had homozygous COL4A4 variant, and 2 (PT904 and PT982; 5.7%) had compound heterozygous variants in either COL4A3 or COL4A4. Digenic variants involving COL4A genes were identified in 3 patients: PT904 and PT1054 had heterozygous variants in COL4A3 and COL4A4, respectively, and PT1311 had a heterozygous COL4A3 variant and a hemizygous COL4A5 variant. This evidence concerns the gene COL4A4 and Alport syndrome.