Pax3: One in a family of Pax genes involved in regulating embryonic development at the level of transcription. The Pax3 gene is on chromosome 2 in band q35. It encodes a DNA-binding transcription factor that is expressed in the early embryo.
Mutation of Pax3 leads to Waardenburg syndrome with a wide bridge of the nose; pigmentary disturbances such as two different colored eyes, white forelock and eyelashes and premature graying of the hair; and some degree of nerve deafness.
The syndrome is named for a Dutch eye doctor named Petrus Johannes Waardenburg (1886-1979) who first noticed that people with differently colored eyes often had a hearing impairment. Pax3 is also known as WS1 (for Waardenberg syndrome I).