Among the included patients, 11 have WS type 1 with PAX3 pathogenic variations, 18 have WS type 2 with MITF (n = 4), SOX10 (n = 13) or EDNRB (n = 1) pathogenic variations, and 5 have WS type 4 with SOX10 (n = 4) or EDNRB (n = 1) pathogenic variations. Here, MITF is linked to Waardenburg syndrome type 2.