TYR and Tietz syndrome: Mutations in the MITF gene, encoding the Microphthalmia-associated transcription factor which plays an important role in the regulation of tyrosinase, a key enzyme for melanogenesis and melanocyte differentiation, are known to cause Waardenburg syndrome type 2A (WS2) and Tietz albinism-deafness syndrome (TS), two overlapping disorders [39,40,41,42,43,44].