Waardenburg syndrome.

Waardenburg syndrome (WS) is caused by autosomal dominant mutations, and is characterized by pigmentary anomalies and various defects of neural crest derived tissues. We report a very interesting case of type 1 WS (WS 1) in an adult who presented all the symptoms characteristic of this syndrome. One particularly important clinical feature of WS is congenital hearing loss, which may severely handicap a child. A careful clinical description is useful to differentiate between various types of WS and other associated auditory-pigmentary syndromes. Type WS 1, characterized by dystopia canthorum, is caused by loss of function mutations in the PAX3 gene.